As when playing live, you can use table talk to your advantage. Table talk is player dependent. I've met very few players who really know how to use table talk; most of the players online don´t think about this topic and give away valuable information. First, we´ll have a look how other players' table chat can be interpreted. Then we´ll see how we might extract info and manipulate our opponents.

Table chat can help us to categorize our opponents.

Type 1:
We all know the annoying short stack, who bought in with 20bb and fills the chat box with "zzzzzzzzzzzzzz" mixed with some "hurry up" comments. Obviously he´s impatient and in gambling mood, which means we should adjust our game in two ways against him:
-Since we won´t have much Fold Equity against him on the flop, there´s no value in continuation betting him, but...
-He´s willing to stick it in with total trash. He´s the one sucking out with J8s against your QQ, so open up your range to raise him All In preflop. As long as you have him heads up, 88+, ATs+, AJo+ is decent range to put him All In.

Type 2:
The table coach, the guy who´s educating the fish. Frequently after getting sucked out (those guys never ever understand the implied odds concept) he starts coaching the donks with comments like "how could you make that call", "did you never hear about domination" and so on. We don´t want him to teach the fish to play better poker, so we´re aiming at all his chips, and he just gave us a hint how to. He thinks he´s the man who would have invented NLHE if it wasn't already there. He doesn't think about what we might have, how we play and how we view the current hand. He just "puts us on a hand" and views our play from his point of view. He doesn't care what we do, but what he would do, which makes it easy for us to under/overrepresent our hands.

Type 3:
People who frequently type "nh", even in hands where they weren't involved, who talk about God and the world. Usually loose-passive, they are at the table to pass some time, who play poker instead of joining chat rooms or going to a bar like normal people. They haven´t sat down to make money or to beat/learn the game, they just want to be with other people. Their calls are irrational, they like to take loads of flops and to draw to whatever. Slow down on your flop and turn bluffs and hit the throttle on the river when obvious draws missed and value bet them to death with TPTK+. Be nice to them, give them a "nh" from time to time and they will give you their chips.

Situations where people talk during a hand are rare, as a rule of thumb we can say that talk usually means strength. A guy check/minraising a 3bet pot on the flop and types "i don't trust u" or something has the goods a large percentage of the time.

Manipulating opponents is overrated in my opinion. We can´t force people into making a huge mistake by simply typing "call". What we can do is to influence their state of mind and how people view us as a player. Like I said before, be nice to the fish. They take their losses as entertainment costs and want to have some fun. If the table is cool, quite and aggressive they´ll play with other people and bleed their chips to others. Some of the table teacher guys are easy to set on tilt, when they´re running cold or get owned badly. Since they view themselves as good to great players, they expect to win every hand they play and have a really result-oriented approach to the game. Standard situations with 0EV or a slight -EV can become +EVs, if the villian gets angry and will get out of line after being "sucked out" (this doesn't mean you should draw stupidly to a miracle card, just be optimistic, when calculating your implied odds). After a beat, ask him why he is playing so bad, tell him "they were sooted", or just let him know that you felt lucky.

Please keep in mind, that observing the table chat or typing something won´t have that much of an impact to your game and that there is WAY more valuable information available at the table. Put these hints at the lower end on your priority list. It might help you in tough situations - when you have really close decisions to make it might turn the balance towards the one side or the other. But table talk on its own is not enough to make a decision.