Home made dip is nice, and can be made the day before with hummus, quacomole, also home made coleslaw is really good. Then just get lots of tortilla chips, and cut up raw veg to tip in.
Also get dried figs (as you are doing it for so many) and wrap them in parma ham. A good cheese plate, and a nicely ccoked ham as threestars says works well.
Cheese straws, make a bulk batch of pastry and then cut into small circles and put various toppings on, like garlic mushrooms, or a tomato with some goats cheese on top.
Devilled eggs are nice, very retro, but just half boiled eggs mash up the yolk with some mayo and some curry powder.
Do min blinis with smoked salmon and sour cream blobs on top.
A good potato salad goes a long way. French dressing ones are nicer in my humble view.
Rice salad, chop some onion finely fry and add 2-3 (or more) mashed garlic cloves and rice to the pan and coat with oil. Then put in a cinnamon stick or two, some currants and pour over lots of veg stock, cover and when cooked. Fold in some dry fried pine nuts.
I think pizzas are easy to do, and just cut into the size of piece you would want.
Your usual sausage rolls, do some chicken drumsticks as well, Nigella is keen on soaking hers in buttermilk first.
Which reminds me cornbread is nice. If it is a fork buffet, then you could do a pot of chilli to go with it.
Cooking a whole salmon always goes down really well too. Goes well with a nicely dressed potato salad.
Easy cous cous salad, just prepare cous cous normally with boiling water, salt and oil. Then when cooked add olive oil and some balsamic vinegar and finely chopped red oinion, garlic, diced whole cucmber, chopped tom, and sprinkle with flat leaf parsley or corriander.
Puddings, Ice cream is a good idea as it can be prepared in advance, and if you get cones its easy for people to eat.
I also recommend trifle as it always goes down well.
HOpe this helps