How to Set or Configer Blank New Tab in Mozilla:-
1. First of all open Mozilla
2. Go to Address Bar or Location bar.
3. Type about:config and press Enter.
4. The about:config “This might void your warranty!” warning page may appear.
5. Click I’ll be careful, I promise!, to continue to the about:config page.
6. Type browser.newtab.url in the search box.
7. Double-click the browser.newtab.url preference and change the url to about:blank
8. Now all set, when you open a new tab, it will be blank. You can also open a particular address too in the new tab.