Here's our menu for our gathering last Sunday afternoon. In our invites we called it a light lunch, with a "start time" of 1:30 PM. Friends stayed until about 4 PM.
whole wheat buns and white buns for making sandwiches
sliced ham, sliced turkey, sliced Swiss cheese (w/ mayo, mustard, butter, salt & pepper available)
lettuce
grapes
baby carrots, broccoli pieces and cauliflower pieces, w/dip (Bacon Ranch salad dressing)
pretzels
peanuts
dried cranberries
frosted pumpkin-shaped sugar cookies
gingerbread cut-outs in the shape of leaves, drizzled with maple icing
a bowl of candy corn
self-serve pitchers of ice water, lemonade, and orange juice
self-serve pots of coffee, decaf and hot water for tea
This is not the least expensive menu we could have employed, but it was the most "self-serve" menu we could come up with, so that I could spend time with our guests.
Here's a tip for setting up the buffet table -- place the napkins and plates first, then follow with the side dishes, following with the sandwich fixings, then dessert. Guests don't tend to go overboard on the sandwiches, leaving little room for the less expensive sides. But they fill their plates in a more balanced way.
self-serve amounts
For amounts of sandwich ingredients:2 to 3 ounces of sliced meat per person (or up to 4 ounces, if you're planning a game day lunch or for an all-men gathering)
1 to 1.5 ounces of sliced cheese per person (a little more, if you are slicing the cheese yourself, or if you're planning for more sandwiches. Remember, a slice of cheese is usually about 1 ounce.)
one-half head of leaf lettuce for every dozen people
For a light-lunch or reception crowd, count on 1.5 sandwiches per person.
For a game-day or meal crowd, count on 2 sandwiches per person, then follow up with additional snacks later in the game, or add substantial sides like potato or macaroni salad.
For a group of all men, count on 2 to 3 sandwiches per person.
For amounts of veggies and dip:
2 ounces of raw, trimmed veggies per person (if you're trimming the veggies yourself, you'll need more)
1.5 to 2 tablespoons of dip per person
For grapes:
2 ounces per person
These amounts will leave you with some leftovers, but you shouldn't have way too much left over, nor shall you run out of anything.
With our group of 15 adults (mixed men and women), we went through just under 2 dozen sandwich buns, not quite 2 pounds (around 28 ounces or so) of meat, about 20 ounces of cheese, 1.5 pounds of grapes, 1.5 pounds of raw veggies and a cup and a half of dip. We also had pretzels, peanuts, dried cranberries and cookies on the table, which filled plates. We went through about 8 ounces of pretzels, 1.5 cups each of peanuts and dried cranberries.