Sony Xperia Tablet Z
NOTE: Sony Xperia Android devices do not have a stock android recovery installed like all the other manufacturers.
you can Unlock the Bootloader on your Sony Xperia device just understand that if you do you may loose your DRM Keys and the TA.img. which removes some of the stock sony apps function and makes it so that you cant take OTA updates any more. This being said if you backup this things first then you will be able to restore them later. There are many ways to do all your modding and hacking without unlocking the bootloader and that is what i am going to focus on with this device.
Sony Xperia Tablet Z Review
How to root the Sony Xperia Tablet Z android version 4.4.4 Kitkat