We do a buffet style meal referred to as "Platter" in our house - kinda like a Smorgasbord type meal. All out on the table for everyone to serve themselves.
Things like slices of cooked and cured meats (regular ham, parma or iberico ham, salamis, braseola etc) and fish (smoked salmon, hot smoked salmon, squid rings, prawns, crab claws).
Things to dip and things to dip them in - breaksticks or flat breads, carrot sticks, pepper sticks, hummus, tapenade, nice pesto etc.
Also olives and cherry tomatoes in bowls. And sometimes the nice coleslaw from a local deli.
Sometimes we might have a few hot things like prawns in pastry or sausage rolls or garlic mussels - mostly though it's just cold things from the fridge.
The Christmas cheeses are opened up and laid out with crackers.
A nice drink for everyone.
It's a meal of treat type food, but relatively light and picky so everyone can choose how much or how little they eat. And it's also a slow, relaxed meal, where people are trying different things and generally just chatting and getting into the Christmas spirit.