These are some spinner cups. You can see there were different designs in the cups, just cut outs to give the cup traction, grip to spin the glass. You can see on the base where a set screw made marks in it to hold it in the fixture it's mounted in on the photos Alan shared. Some have holes in the bottom, some don't. I would presume to vent air in order to keep bubbles out and to let the glass fully seat into the cup.