When you play live poker you table image is based on body language, speech, posture, etc. Online you still have a table image which other players will pick up on. If you have not used the note feature on Poker Stars I suggest you start doing so to track other players table image. Some people use tracking software or other tools to help track players and how the play how the do in SNG's and MTT's. 

So what is your online table image based on? For one auto checks, auto bets, auto raises in FL, etc. People will take note of how you auto play certain hands. This becomes a tell. It can be an advantage and a disadvantage to you.

How often do you limp in. A lot of beginners and even intermediate players will play to many hands in lower stakes thinking that the equity is there.for instance my usual stats when playing .05/.10 FLHE is in the BB no raise 100% play to the flop. if raised it is more closer to 30%. In the SB I play 50%  without a raise and closer to 15% with a raise. Early position at a 10 player table Seat 3-5 about 10% play. Seats 6-7 about 25% and seats 8-10 about 35% play. That is a lot of folding I know however this provides me with a tight table image. So the players that are taking note of this will get out of my way when I am in a hand on the flop if I make a bet or raise preflop or reraise on the flop. 

The Stats tab will show you this information for your session. If you are playing a total of 50% of hands outside of the blinds you could be considered a loose player or a tight aggressive player depending upon other factors. If you are playing over 75% of hands outside of the blinds you are giving to much money away and are going to experience huge swings. You will want to check this after a half hour of play. Reset the stats if you need to see if you improve your image. Observant players are not going to forget your image so if you start to change it you are going to through them off!

When playing PL or NL betting patterns come into play. How much do you bet your hand strength and from which position? Since players can not physically see you they are going to measure how fast or slow you bet, are you betting the same amount on the button with Pocket Aces as KQ suited? Are you aggressively betting in early position or betting timidly? Do you make continuation bets? Will you call even though you are beat on the river?

Practice your table image as soon as you start playing start tracking other player's image you will notice patterns and you will find a deviation and know something is not right. Either they are over bets or under bets or limps when they would raise. This is when you should have bells and whistles going off that something is going down. Take advantage of these situations to gather information. 

In tournaments it is crucial to maintain a solid because it is a long way to the money and to the win. There will be times that you can deviate from your table image to through off your opponent but you must have built a strong image and your opponent must have seen every bit of it constantly over and over again. This is when you can begin to deviate from betting patterns or timing in action to send your opponent for a loop. These are the few tools you have to get inside an online players head. Do not stoop to trash talking or bad mouthing a player. See my blog on Poker Etiquette.

Good luck at the tables and practice that image.