Places to take elderly parent to eat a home-cooked meal when visiting them from out of town?

Some Gov Bldg and churches have pretty grounds and can be easier to navigate. He could go into a courthouse and apply for a marriage license, look up an ancestor or maybe get a copy of some document from long ago.
If he has friends or families who have passed he might enjoy taking a flower or stone to their graves.
Look up historical sites that might have monuments or statues to visit.
Airports, bodies of water, like a dam or nice bridges or ferrys where birds hang out or people fish or ducks swim by.
University or school campuses might be accessible and have scenic spots. Large hotel lobbies can be enjoyable and sometimes a pianist is providing back ground music if you need a place to pop in and be refreshed. I have a friend who lives in a tiny condo in Chicago. She thinks of the large hotel next door as her living room where she meets friends.
Large hospitals sometimes have the same ambiance.
Public golf courses. Any large manicured area is beautiful to look at driving by, through or parked in a nice spot.

Places where he could hold a puppy or see aquariums would be fun to visit. We use to take our young daughter to a feed store that was located in the middle of a huge city where they often had parrots and a variety of chickens and pigeons. Sometimes several breeds of bunnies. Often a box of furry kitties or puppies. She called it the “littlest pet store”. That could be before or after a meal. If you find some places that pique his interest to visit then he might agree to eat at his facility after the visit out. That would make it less expensive for you and he would still get out.
Little league parks where kids are playing baseball might be fun.
Book stores often have comfy seats and large restrooms. Maybe not a place to eat but I know If someone took me to a bookstore when I am past driving for myself I would love it. They often have a coffee shop attached.
Some large grocery stores have booths or tables and chairs and you can buy a sandwich to split or get a cup of soup and watch the frazzled mom’s for a few minutes with their toddlers.

Farmers markets can be fun and with the proper supplies, a paring knife, a few wipes, a fresh peach or pear can be enjoyed or sliced tomatoes and fresh bread. A couple of folding lawn chairs can enable a picnic almost anywhere.
You might go to a visitors center or chamber of commerce office and find brochures and suggestions for the Area.
Antique malls can be fun to spend a few min in if they aren’t overfilled. Also sometimes you can find old fashioned 5 and dime stores. Thrift stores can be fun and places he will see other seniors out and about and of course there are senior centers where you could get a different meal.
Western stores or farm implements stores or hardware stores can be fun to poke around. Perhaps you could take photos of him at the different places you take him and make a scrapbook or photo album for him to look through when you are away. You can stop in many drug stores and print out your photo of the day and have it ready to paste in the book the next day. Then he gets to enjoy his ventures more than once.
Many art galleries have openings and tasty morsels along with wine on certain Fridays of the month. That might be more for you than dad. I’m making myself tired.

I suppose consider dad’s interests and yours and then think what is easy for him to navigate. Does the facility have a transport chair you can borrow? I think you can sometimes rent those. I agree that the food is secondary to just getting out and creating a feast for the senses. Small bites otherwise.
I love your idea. Let us know how it goes.

I used to "car picnic" with mom and dad. There was a particularly beautiful overlook on a quiet road that looked across the valley and up to a mountain. We would open the windows and listen to the crickets and if we were really lucky, they would have just mown the field next to the road. I always brought wipes, extra napkins etc. I suppose you could even bring a breakfast tray. There are even half-way decent-looking travel bibs for adults (they come in a little stuff sack, that look like the front of a shirt that I got for dad because his hands shook due to a medication he was on. My parents didn't wear hearing aids, but I can imagine that car picnicking would be easier for someone as there is less ambient noise for someone who does. This way of eating out became more comfortable for them as they became less ambulatory.

My sister who works in an AL/NH says don't over think it, it's the opportunity to get out that is more important than the food. Instead of planning a meal plan, just stopping for ice cream or coffee, even a McD's burger or fries are a treat when you don't get anything like that at the facility.

My mom never liked to go out to eat and as she got older she preferred to eat at home. I was lucky to have a gazebo in my yard and we ate there she loved it. It was lovely and now has extra warm memories of eating together. It's all about their needs or wants as they gracefully grow old.

There's a brilliant website called Ontarioparks which, besides the picnic info, also talks about camping type accommodation - I spotted a section called "roofed" and looked at that. So maybe the picnics wouldn't have to be weather-reliant?

But does he like the great outdoors or is he hankering after a bit of downtown?

??? Why do I think you're in Ontario? Am I just having random thoughts :/ or did it come up before???

I think I'd look for an air bnb that is handicap accessible and allows kitchen access.

Look for local fire department/ church suppers, fish fries and pancake breakfasts.

How old is dad? What are his medical conditions? Does he have dementia?

How nice that you want to plan some outings with him while you are there. Do, consider his ability and your limitations on what you can do.

Ask the facility where he is living to see what ideas they may have. And they are very familiar with his abilities.

My Dad was very uncomfortable going "out to eat" . Plus it was very hard on everyone. How about you making him a home cooked meal at his home. Remember they are from a generation that had simple food ( The Great Depression for the U.S.). He may even be able to "help". Then a drive after( playing music he loved when he was younger). with a stop at the ice cream shop. I know that sounds too simple but simple is best for you and your father. Ummm..That would be a nice treat for everyone

How about the mall? There are places to sit and people watch. Or pack a lunch and go to food court. I think there are chairs/scooters you can rent for the elderly to get around. Some malls have that. The person can still walk, but just not that far. It is an option for them to get around easier. Altho some elderly refuse bc they dont want to be seen in a chair if they can walk.

There was a lady at the nursing home that would get a wheel chair van. It was like a cab that would take her to the mall to meet her family for lunch. Thought that was really cool she could do that. It got her out and made her feel like she was still part of society.

Some local restaurants offers senior early bird discounts. Ask the LTC as they may know. What I do with mom and she is always just delighted with the bargain. And my pocket too of course! Enjoy your visit!