This is a very large vintage cut glass ashtray dating to the mid 20th century. I would put it at around the 1960s. It is very heavy and nicely made with a simple cut design. The slots that hold the cigarettes are large enough for a cigar and it may have been intended for that purpose. It is unmarked.
It is 7 inches in diameter and about 3 inches tall. It is in very good condition. There are a couple of very tiny fleabites to the edge of one of the cuts on the bottom but this is hard to see unless you are looking for it.