Here are some kinds of Tournaments. Some of  the Tournaments are played on several number of tables.

Multi-Table Tournaments - This kind of Tournaments is played on several number of tables, depending on the number of the entered players. The action takes place at the same time on each of the tables. When participants are busted of the tournament, players are moved to other tables to keep numbers balanced and games more enjoyable. When enough seats are free a whole table will be removed, until only one table remains. The Tournaments last till one of the players collects all the chips put in the game. 

Satellites - In the satellite tournament, instead of cash prizes, the winner is awarded tickets to another tournament. The ticket is valid as a buy-in, so you will not have to pay any additional fee. 

Added Cash - An added cash tournament is a tournament with prize money added by the online poker room on top of the regular prize pool. This is a bonus for the participating players. The added cash can be distributed between all the cash winners, or sometimes only to the gamer in pole position.

 Free Rolls - At this kind of tournament can be entered without paying the buy-in, but there is a money prize for the winner. Usually the amount is not that big like at the other tournaments. 

Single Table Tournaments - This is a contest where a player plays a game at a single table with a group of other players until all players but one are eliminated from play. Players are ranked by how long they can stay in and the prize pool paid out on a sliding scale amongst the top finishing players. the seats of the eliminated players remain vacant until the end of the event.