Are you able to cook on the stove or in the oven? Usually you can bake in a toaster oven too. If you go to a grocery store that has a butcher many times they are able to cut up meat into smaller pieces. Many salad dressings, I like Italian, is good a marinade for them.
Some stores sell pre-made meatloaf and it can be broke up with a fork instead of a knife. There are many frozen/microwave dinners that have smaller pieces of meat in them. Stores usually sell pre-made hamburgers and you can cook them in the oven.
We make subs like they do at Sub Way. We'll put lunch meat on the pre-cut bun and toast them in the toaster oven. You can break up lettuce and what ever else you are able to and put that on them.
Baked potatoes and yams can be cooked in the microwave and can usually be cut with a fork. Spaghetti, Alfredo or another type of pasta sauce is a good idea just pick a smaller noodle.
Many stores have pre-made chicken salad, egg salad, tuna salad and things like that. You can make sandwiches out of those. At the deli a good bit of times they have things made up with smaller pieces.
A Slap-Chop works good in cutting up hard vegetables that you can add to things.