As Flow already pointed out in his comment to the question, that is a known bug. However, if you're affected, there's at least a kind of "ugly work-around", as described in the article How to solve battery issues after ICS update in your Galaxy Note. Their conclusion states:
Anyway, this is a kernel bug in ICS, we have to wait for new update. The solution for this is: shutdown your Note, peel off the back cover, remove the battery; hold the battery for more than one min, put the battery back, put back the back cover; start the phone. Then, everything goes back to normal. Reboot your phone will NOT solver this issue, at least for me.
Next time, when you encounter this issue again, try the procedure again.
They further write that, if you once encountered this bug and worked-around this way, it seems it is hard to hit the bug again -- so with some luck, you will only have to do this once.
And yes, I saw that article refers to the Galaxy Note. But talking about a kernel bug in ICS, and your tablet being from the same manufacturer, chances are pretty good this solution will apply to your tablet as well.