Since your tab has already gone through the bootloader unlocking process, there is neither a need nor a requirement to wipe the device.
And since you want to stay as close to Stock as possible, you can even "root" without ever flashing a recovery: you just soft-boot a recovery image rather than flashing one. That is - "fastboot boot (...etc)" instead of "fastboot flash (...etc)". That allows you to use a custom recovery every once in a while while leaving a stock recovery on the tablet. That preserves maximum compatibility with future OTAs.*
And with that soft-booted recovery, immediately take a Nandroid backup including the Stock recovery (which is still on the tablet because you soft-booted the recovery you are using). In the same session, use "adb pull" to get a copy of your 100% pure-stock Nandroid backup off the tablet. (Make sure you name it clearly so you will know exactly what it is 12 or 24 months later)
Finally, use a flashable .zip installer package for SuperSU to "flash root".
After an OTA, you can just reinstall root by soft-booting a custom recovery and using the same (or updated) flashable .zip installer method for reinstalling SuperSU. And just like above, capture a new 100% pure-stock Nandroid backup (including the new stock recovery) *before* re-rooting.
This strategy allows you to roll back to any version of stock you please at any time in the future.
* flashaholics prefer to have a recovery hard-flashed on their device so they can flash things on a whim, wherever they are. The approach here is a bit more restrictive as you have to have a PC handy in order to soft-boot a recovery in order to do any flashing. I would say that the biggest limitation of this approach is that it tends to reduce the number of Nandroid backups of your ROM personalization.
Backup are a good thing. You can always throw them away later, but you can't create a missing one that is urgently needed.
"I'm gonna start coding placebo apps. That way I will be sure that the complaints are real and the praises hollow."