Create Following all folders in Res folder of your Project.
values-large-mdpi (This is for 7" tablets)
values-xlarge (This is for 10" tablets)
Now create xml file in each folder abs__dimens.xml and Give different text size in <dimen></dimen>
<?xml version="1.0" encoding="utf-8"?>
Now set this in to text view property-text size
It will work fine for all Android devices and Tablets, Hop It will help you some one !