Tickets are used as an entry fee to different types of Tournaments (Solo Challenge, Lightning/Bonus Arena, etc.) that will help you level up through the game. You can earn Tickets if you win Tournaments as well. Also, you can use Tickets to purchase Power-Ups while playing in the Tournament.
 
Here are the steps to start a Tournament:
  1. Tap the Tournament icon (trophy icon) to get started.
  2. Use Tickets to enter Tournaments and unleash Power-ups.
  3. Tap on the Classic Table to enter your first Tournament.
 
Keep on playing to level up and unlock different tables in the Tournament.