Steps:
1. Connect your tablet with your host computer
2. Open prompt and locate to your adb folder (platform-tools) and enter
Code:
adb reboot download
If it doesn't work, look at your tablet to see any prompt to allow your host computer
3. Open your Odin. Make sure auto reboot is not checked (but TWRP isn't overridden). Choose AP and locate your TWRP file. You may see secure check failed. Don't worry. Just press and hold power+volume down+home key together and wait for few seconds.
4. Enter TWRP by pressing power+volume up+home key together. You should see the boot screen. Keep pressing these buttons until the boot screen disappears. You should enter TWRP.
5. Locate your memory card. Flash systemmode SuperSU first, go back, and flash padded image as "boot".
6. (Optional) wipe cache and dalvik cache.
7. Reboot
8. It may take a while to boot up
9. Your tablet is rooted.