Feed the dogs the same things you feed them every day. Or better yet, have fun activities like swimming or the dog park, but no food.
It's totally fine if your dogs are used to eating a lot of random stuff; then their stomachs can handle it. Historically dogs lived off human table scraps and garbage heaps.
But if they're like most pet dogs today, they probably eat the same dog food day after day. If all of a sudden you give them a lot of new, special food, even quality meat or treats, it could severely upset their digestive tract.
And by "upset" I mean you'll have some very bad news squirting out both ends for at least a day, maybe two. It's not pretty. The smell can be beyond your worst nightmare. If you have carpets -- oh, carpets! -- God help you.
I say this from bitter, bitter experience. If you must have food at the party, give them some of their regular kibble, but make a big show of it: smile, have them do a trick, act like it's the best food you've ever given them. They'll love it.
Dogs are simple creatures and they thrive more on human interaction than on any thing you could give them.