I was going to proclaim "ice buckets" until I saw how small they are - I have seen glass ice buckets in this style, but obviously much much larger! And that you have a set of 6 made me wonder if they are shot glasses made to look like miniature icebuckets, perhaps for something you might drink very cold, but then I thought the sticky up bits would make drinking out of them a bit of a challenge, so my second thought was are they egg cups? Or a third thought, maybe toothpick holders - the sort you might set around a formal table for when the food is finished and the guests want to pick the bits out of their teeth?