The changes that are listed on the Google Play Store, where the browser can be installed for free, include faster start-up for tablets and a new design, new security and privacy options like Do Not Track, enhancements to tabs including the ability to swipe to close them, the ability to find specific text using "Find in Page" and the option to request desktop versions of sites. Bookmarks and history can now be imported from the stock Android browser, the Download Manager can pause, resume, cancel, or retry downloads and certain personal data can be removed from the Settings menu. Mozzila has even added a new HTML5 based multi-player role playing game called BrowserQuest that can be played over the desktop or mobile Firefox browser.
Since the update brings the same features and functions of the Android smartphone version of the browser to Android tablets, you might want to check out the video below.
source: Mozilla, FirefoxforAndroid via MobileBurn