Are you asking how to be able to move apps over to the card? If that is the case, you would have to 1. be running Android "Marshmallow" and 2. have a tablet that doesn't restrict changing the SD card to "Internal" storage, vs the standard "External" storage they usually are.
If your device is running "Marshmallow" then you will have to start with a blank SD card, as when the card is formatted and encoded to work with only that device, anything already on it would be wiped.
How to turn external SD card into internal storage on "Marshmallow".
1. Go to device “Settings”, then select “Storage”.
2. Select your "SD Card", then tap the “three-dot menu“ (top-right), now select “Settings” from in there.
3. Now select “Format as internal”...