There’s a flag under the blackjack table that you can kick in order to expand the table. Sometimes you only have a few people playing blackjack so you don’t need to kick the flag at all, and sometimes there are many people playing blackjack so you need to kick the flag many times in order to expand it to a proper size.
The blackjack table does have a limit though of how many times it will expand, and that limit is ten (てん). You can only kick the flag to get the table to expand ten times.
Currently there are no similar looking kanji which exist in the WaniKani learning system