Action is table slang with two everyday meanings. The first is about turn order: when the dealer says “the action is on you”, it is your move, and you have to check, bet, call, raise or fold before play moves on to the next seat, usually clockwise.
The second meaning is about money. Action describes how much a player, or everyone at a game, has wagered. A table with “a lot of action” sees big or frequent bets, and a player “looking for action” wants a busy, high-stakes game.
For operators, the second sense is the one that shows up in reporting. Total action, also called turnover or handle, feeds into revenue reports, the tracking of bonus wagering requirements and the calculation of loyalty points, so it is worth measuring per game and per player segment.