I would make 1/2 roast beef, 1/4 each turkey and ham. Small rolls, 2 per kid 3 per adult, 4 per teen. Per roll 1/2 ounces meat (basically, 10 sandwiches per pound).
I would definitely add some kind of green kids on the listsalad. I would probably add some kind of chips if there are teens and
You need at least 4 serving lines.
You also need appetizer tables, here's why:
Before the Buffet; Why You May Need an Appetizer Table
A self-catered buffet is a real challenge to the organizers, and things don't always come together as smoothly as hoped. By planning and setting up an appetizer area or "nibble table" which is ready when the guests begin to arrive, the cooks and servers have time to complete the arrangement of the dinner buffet. This is especially critical if there are children among the guests, or there is a wait before dinner, as at a wedding reception.
This does not have to be complicated. Three items, including a fruit tray, a cheese tray and an attractive dip or spread, plus a punch, or two if one is alcoholic, are sufficient.
One appetizer service area is needed for each 100 guests.