To add a "Standard Tab" to family Browser is very easy.  Just click on the "+" symbol below the last tab and that will create a new tab called "FB New Tab".  To rename this tab to anything you like, double click on the text and rename.  Once you are finished, click on any other tab and that will rename it.

To find out more about tabs and what the difference is between a "Standard Tab" and a "Live Tab" refer to this article - Difference between "Live Tab" and "Standard Tab"