A rule in a poker game meaning that a player may not go into his pocket for money during a hand. He may only invest the amount of money in front of him into the current pot. If he runs out of chips during the hand, a side pot is created in which he has no interest. All casino poker is played as table stakes.
The definition sometimes also includes the rule that a player may not remove chips from the table during a game. While this rule might not be referred to as "table stakes," it is enforced almost universally in public poker games.