Multiple Tabs

You can have it open pages in new browser tabs by going to the page on the page list and then clicking on the dropdown to the right of it to open in new tab.

Unless you are talking about opening multiple pages within the same browser tab, in which case nope it's not presently possible.

Another way to open a page in a new browser tab is by middle-clicking (using the mouse scroll wheel) on the page name in the left panel.