Talk soon” means nothing at all. It’s a parting phrase, like goodbye, take care, be well, see you around, until next time, cheers, etc.
Just about every time two people meet they say the same things (I’d like to know you better, I’ll call you, talk to you soon, etc) because frankly, what are people suppose to say on their first meeting? I really don’t like you, I find you annoying, etc. Of course not. People are generally polite and say things like “talk soon”. Then they go home, think about it, and they may or may not want to get to know you anymore or talk to you again.
You must also consider that if he met you through the internet, there’s a good chance he’s meeting other women that way too. Only a fool would stick to just one person when it’s fairly easy to meet a bunch. I’d venture a guess that you’re one of many women hearing “talk soon”.
He’s not expecting you to call. He may just never call you. But why wait around not knowing? You have got nothing to lose by calling him and seeing where things stand (not in terms of a relationship; in terms of another outing).