Why multi table? Most players multi table for two reasons. To make more money, or they are just action junkies. More tables equals more money if you are a winning player.
You can earn a decent amount if you can play effectively when playing a lot of tables. If you have a small bankroll it is how can maximize your profits without taking too much risk.
When you play one table for a large percentage of your bankroll, you are at risk of losing your whole bankroll with a few bad breaks. If you play 10 tables at once, for the same total buy ins as the one table, you reduce the risk. It will take about 10 times as many bad breaks to lose you bankroll. But, you profit potential is the same.
You might even find that you can make more money in the multi tabling examples. The reason for this is that the single table game you play, for ten times the buy in, has much better players. Playing weaker competition, you should increase your earnings.
Here are some guideline to successful multi tabling. Don't start to fast. If you jump in and start playing 6 tables at once you will probably start losing. Go slow, and add one table at a time. Once your under contol with two, go to three, etc, etc.
When multi tabling, play a simple game. Your decision time is reduced. If you play a complex game, there won't be enough time to make all the hard decisions. If you are pressed for time, you will make more mistakes.
Don't play so many tables that you are only on auto pilot. If your big decisions are done on auto pilot, you are playing too many tables, and you need to cut back. You still want to have time to think about tough situations, otherwise you will start losing.
Don't just play all day at the first tables that come open. When you find the styles at the table make for a lot of tough decisions, consider finding another table. You want to be at tables where the play is straight forward.
Don't mix your games. If you play two tables of omaha high low, and two limit holdem, and two SNGs, you will really test yourself. If you play just one game, at all the tables, you can get into a groove.
Online poker has made multi tabling a new way players can attack the tables. You have the opportunity to make as much money as a much higher stakes player who plays live. Many of the good players are taking advantage of this opportunity.