I have never given tuna. Most of it comes from other countries and the contamination content concerns me. That doesn't mean it is necessarily a bad thing though.
For people food, Ellie has gotten chicken, turkey, beef, whitefish, egg, cottage cheese, peanut butter, potato, sweet potato, white rice, brown rice, barley, oatmeal, peas, squash, carrots, green beans, celery, cauliflower, broccoli, green pepper, lettuce, yogurt, banana, strawberries, blueberries, apple, melon, ginger snaps, candy
, cereal, etc.
I would not recommend giving this much or a variety though and the fat content and seasonings used in these foods is very important to pay attention to.