Just to clairify, I believe we are talking about two different things here, correct me if I'm wrong.
OP is having issue where when he has the tablet powered off completely that it then powers itself back on automatically when plugged in.
Others mentioned screen automatically turns on when plugged in and wants to stay on in some cases and even when turned off, the tablet doesnt deep sleep.
If this is correct, then I'll continue with this. i have had this happen to different devices and seems to be a feature of the ROM. One of the last ROMs I ran on my phone drove me nuts with this. I could never charge my handset with it powered off. When it was near dead and I was leaving soon, I would want it to be as juiced up as possible in a short amount of time so I would power it off and charge. Then one day after flashing I could no longer do this. Then I switched ROMs and I can again. I havn't tried this on my TF700 yet, but would find it annoying if I needed to. I have seen this happen on other devices before realizing it was connected to my ROM, although I could work around by selecting shutdown after it booted up. But with the ROM on my note it would shut down and come right back up.