Stick to vegan foods I say. It's not going to kill them not to eat a dead animal and enjoy your company at the same time!
A few easy yet delicious vegan foods are:
Sausage rolls! - you can either make them yourself, buy premade vegan ones, OR buy some sanitarium sausages and wrap them in some vegan puff pastry (Borgs brand or pampas are both vegan and you can buy them in the frozen section of coles/woolies)
Samosas - you can get these premade or make them yourself
Spring rolls - See samosas.
Vegetable skewers - SO EASY TO MAKE YOURSELF!
Punch - see vegetable skewers - would be worried if punch had meat in it.
chocolate fountain - use dark chocolate! Have some cherries and strawberries alongside it for dipping.
cracker plate - you can make and purchase vegan pate, olives and cocktail onions are already vegan, buy some sanitarium polony slice and chop it up. You could even have a crack at making a block of vegan cheese yourself (
http://thecompassionatecook.blogspot.com/2011/04/melting-mozzarella-cheese.html) it tastes just as good when you don't melt it, and is the same consistency as cheese. And just have some crackers and maybe a side of hommus.
Original flavoured Doritos and salsa - all the hard work has been done for you.
Wedges and sourcream/sweet chilli - make your own wedges with some potato, and use tofutti sour cream along side some sweet chilli sauce.
And who doesn't love a good spinach cob loaf dip?
http://thecompassionatecook.blogspot.com/2011/10/vegan-mofo-day-7-spinach-cob-loaf-dip.html
Hope this was useful for someone out there