For some reason I can't reply to winslow, so this goes here: Yes, you can open tabs. But that's rather useless (unless you want to use it as a general browser). I phrased that badly. What I meant was that you can't open links in new tabs. Which is what I'd like to do when browsing through sales or genre lists.

If you are talking about the in game Steam browser (based on chrome) yes you can open new tabs with Ctrl+T. Though their desktop version isn't meant to be a browser hence the limit to steam store and on tab.