A paytable is the information screen inside a slot that shows what every symbol pays and how the game works. It is usually opened from an "i" or menu button and updates its values to your current stake.
A good paytable covers:
- the value of each combination, from low-paying to high-paying symbols
- what wilds, scatters and bonus symbols do
- the paylines or ways the game uses
- how each feature triggers and plays
- the RTP of the version you are playing, and often the max win
Reading it before you play is the best way to find out what you are actually betting on. It is also where to check the RTP when a game comes in several versions (see RTP range).
The paytable describes payouts, not chances. Odds of each combination are not usually shown, although some games list how often the bonus triggers.