we used the smallest size cake 6" I believe and we had tables of 8- I know there was more than enough cake to go around, even for people to visit other tables and sample additional flavors. I was worried also that the cake wouldn't be enough of a centerpiece but I think it was perfect--my venue put mirrors under the cakes and my DOC sprinkled a few of those colored fake rocks (you can get at Michaels) under the cakes stand( we just used the ones from QOC). I have no idea if there was a lot of cake leftover--I wish there was, because I oonly got 1 little piece the day of and not even the flavor I intended on eating LOLYou will be very pleased with your choice of cake vendors!