I would have told them all to F* off but seeing as you haven't.
I'd go with a carrot and coriander soup to start. Saute some finely chopped onions in olive oil, season with salt and pepper, chop the carrots and add. Add stock and chopped corriander (keep some back to garnish). Bring to boil, simmer, blend, taste, reseason, freeze.
I'd also go with the beef for the additional meat. Or how about a nice big gammon (for the traditionalists). Bread sauce - muck - buy a packet.
Like the table ideas, how about getting some nice cheap tree decorations in whatever ever colour you are going with, perhaps, dark green or gold to set off your red sheet and piling in a nice couple of bowls along the middle of the table. They should be going nice and cheap by now.
Delegate the drinks, the clearing up etc and be firm.
A great game is what we call the bowl game. Get a big bowl. Give everyone 5 pieces of paper and get them to write famous people on each, mix in the bowl. Split into teams. Each team gets a minute to pull out scrunched up paper and describe the person. Team with most at end wins. Round two, all papers back in bowl, this time teams can us one word to describe person. Same timings, same outcome. Round 3, teams have to mime person, same timings, same outcome. Great game, will pass hours.
Not really a desert fan, I'd just give 'em Christmas pudding and if they dont like it, tough.
I hope you get good presents!!!