I did Cream of Chicken soup in a crockpot for my daughters Baptism and breadsticks on the side along with some other appetizers.
You could do an artichoke dip with those little slices of bread or crackers for dipping. You could have it all made up and then toss in the oven for approx 1/2 hr. You could do meatballs and little smokies in a crockpot. There are some pretty yummy pulled pork recipes out there for crockpots and you could even have that done the day before and heat up in a crockpot the next morning with BBQ sauces, etc..and you could have pulled pork sandwiches. There are lots of appetizers you can make in a crockpot, crab dips, artichoke heart dips, rubin dips, etc. I'd stick to crockpot ideas (if you have multiple, or borrow one or 2) that way, they can cook while you're away and will be ready when you return with relatively little work.
I just thought of another one,...those little roll-up sandwiches or cream-chx rollups are easy, and you can make those the day before too. You can even buy those at places like Costco or Sams. I prefer the cream cheese ones myself. :)