To find your browser, go to Settings, About Phone, Software Information, More to find the browser and version.
I think you can only have 6 tabs open. I tried this on my phone. Once on the Internet, I tapped on the Menu button at the bottom of the screen, the one with the horizontal bars. I selected a website that I had bookmarked. To open up another tab, I click on the Menu button again, but this time select Window...I get a blank page. Then I can select another one of my bookmarked websites. Now I have two tabs and I can go back and forth by swiping left or right. You can continue this process up to 6 windows. To close any of the windows, use the X in the upper right corner of the tabbed window.
HTH...Kurt