Thanks in advance!
Sent from my Nexus 10 using Tapatalk HD
You can actually backup your device with TWRP and it will do a complete backup of your device, even if you aren't rooted. However, I'm not sure if you can restore it if you are unrooted. What you do is flash the recovery through fastboot, which requires adb on your computer. It's a little complicated, but that's how I backed up my device before I unlocked the bootloader and rooted it.
Can you flash TWRP though if you bootloader is locked? I am guessing that since the OP is not rooted, he/she probably doesnt have the tablet unlocked either. And with a bootloader unlock it wipes all data, so it wont help if TWRP or CWM cant be flashed with a locked bootloader.