Cubes of favorite cheese stuck with a pretzel stick
Cream cheese spread
Yogurt dip
Cottage cheese (only if they like it)

PROTEIN:

Cubes or rolls of lunch meat/cheese
Peanut butter
Hard-boiled egg
Tuna, chicken, egg salad spread

FRUITS/VEGGIES:

No cooked veggies allowed
Fruit slices/ with fruit yogurt dip
Veggie sticks with plain yogurt based dip
Applesauce
Canned fruit in its own sauce
Raisins, dry fruits

BREAD/GRAIN:

Crackers with spread or dip
Miniature muffins
Rolls with butter
Pasta with mild Parmesan or Romano cheese

Using TV dinner trays or your children's play dishes, arrange foods from the above listed food groups (or use your imagination) on the trays. Surprise plates can be served for lunch or dinner (especially when the adults are having something no self-respecting child would ever touch).

How you serve the surprise plate is very important. How about a table cloth on a washable floor for an indoor picnic?

You can also try preparing your own surprise "TV dinner" plates for the freezer. When all else fails, just open the freezer and take out an unlabeled surprise plate.