I'm feeling that my tablet feel a little sluggish. I wonder if it would help if I rooted and installed some other rom would help? Is there a guide for this?
1. It's the ROM that gets rooted, so rooting, then replacing the ROM is wasting time rooting. If you replace the ROM with an unrooted ROM, the phone won't be rooted.
2. :Some other ROM may be worse than the one you have. Find ROMS (on XDA Forums) and try them. Some are faster, some have more features, etc.
(If you can, install TWRP first and back the phone up so you can always go back to where you are now if anything goes wrong.)