It happens to everybody, but some apps cause no wakelocks and some apps keep your tablet from sleeping at all, it just depends what kind of apps you like, you how bad your wakelocks depends on what apps you use.
You can use an app killer, but some app restart themselves, there was an free app called "package disabler" it does not need root to work, but it has vanished from the play store, and only the paid version remains.
First thing to do, it check for alarms and disable them, check for apps that sync including your google account, disable syncing.
If you are rooted you can install lots of apps to prolong your battery.
Originally Posted by mohammadreza.n
Thanks Tinderbox for your long comment . So as I understood from your comments this is not a known issue!