As I have said before, you really need an appetizer plan, and here is why:

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, plus a punch, or two if one is alcoholic, are sufficient. Typically, include a fruit tray, a cheese tray and an attractive dip or spread; or you can go with a dinner theme such as TexMex with chips, salsas, Texas caviar and guacamole; Italian with bruschetta or antipasto; maybe shrimps or other cold seafood, if budget permits.

One appetizer service area serves about 100 guests, you plan 3. With this informal menu, chips and salsa, Texas caviar, fruit plates, cheese and crackers are kind of a minimum.

We have talked about this menu often before. It needs filling out for this level party

bbq pork, 1 pound makes 6 sandwiches, 60 pounds ready to serve
360 full buns. Slider buns, 12 per pound, are a better choice for this size party
1 gallon pickle slices per 100
8 pounds sliced onions per 100,
2 gallons table sauce per 100

chicken strips, 1 pound per 5, but baked chicken legs or quarters would be a preferred choice- 1 piece per person, a quarter counts as 2 pieces.
If strips, dipping sauces, 1 cup per 5
rolls- about 15 pounds other good rolls, 3-4 pounds butter

mashed potatoes, 35 pounds raw potatoes per 100
gravy or butter, 1 cup per 8
Mac and cheese, 30 pounds dry pasta, 1 quart sauce per pound pasta, 1/2-1 pound cheese per pound pasta

green beans 65 pounds ready to cook