In poker, table stakes limit the amount a player can win or lose in the play of a single hand. A player may bet no more money than he or she had on the table at the beginning of that hand and conesquently can not go back to their pocket for more money once a hand is dealt. In between hands however, a player is free to rebuy or addon so long as their entire stack after the rebuy or addon does not exceed the maximum buy-in.
This rule generally applies to cash or ring games of poker rather than tournament games and is intended to level the stakes by creating a maximum and minimum buy-in as well as rules for adding and removing chips from play when playing with cash. A player also may not take a portion of their money off the table, unless he or she leaves the game and takes their entire stack out of play. Common among inexperienced players is the act of "going south" after winning a big pot, which is to take a portion of your stack out of play often as an attempt to hedge ones risk after a win.
Table stakes are the rule in most cash poker games because it allows players with vastly different bankrolls a reasonable amount of protection when playing with one another. Contrary to classic Hollywood poker movie scenes, money taken from the wallet during a hand, does not play under table stakes.