I've done it a couple times now. After the first time I said "never again" and only agreed to the second because certain people were going to be overseas .

My advice - lower your expectations. Drastically. People arriving on time - not gonna happen, people allowing kids to open presents at their own pace - not gonna happen, allowing a minute or two for you to locate instructions/all pieces/a camera before moving on to another present - not going to happen. More than once, instructions or pieces have been thrown out with the wrapping because grandparents want the kids to open 10 presents at once. Another thing, plan your menu. Then take 4 or 5 things off, unless you like having a stressful morning/day/week before cooking, cleaning and cooking some more only to have most of it go back in your fridge or in the bin. If you can, ask others to bring things instead. And a nice quiet room you can disappear too when everyone's getting drunk & obnoxious. Clearly my experiences have not been that great . But if you expect the worst, you are less likely to be disappointed.

Anyway, what I did was:
Food - I planned it all out and asked everyone to bring 1 or 2 things. We did a roast chook, a crunchy noodle salad, fruit platter & rum balls, others brought ham, other salads, platter of cheese & bikkies etc for nibblies, other desserts. FIL brought prawns unasked lol. We supplied a couple esky's with ice for everyone's drinks.
Table - pale gold tablecloth, white dishes, red christmas serviettes, red bonbons and a few decorations on the table with some tinsel around it as a centrepiece. Simple but looked great if I do say so myself lol.