Well, if the tablet is running any version of Android lower than "Marshmallow", aka 6, then it won't. However, if your tablet is running "Marshmallow" or can be upgraded to it, then you have a shot. Another possible hurdle is that sometimes manufacturers restrict this ability, if you are running "Marshmallow".
How to turn external SD card into internal storage on "Marshmallow".
NOTE: Please be sure you start with a blank SD card. It needs to be blank because when the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device).
1. Go to device “Settings”, then select “Storage”.
2. Select your "SD Card", then tap the “three-dot menu“ (top-right), now select...