In fairness to the creator of the tablet picture, Kirk's padd reminds me more of Apple's Newton
. However, that also provides evidence against the original picture, since the Newton can be traced back to the 80's. Both seemed stylus operated, versus touchscreen, which the iPad and Picard's were. Plus, you know, the advantage of color graphics.
Either way, in my opinion, the Newton and Kirk's padd resemble PDAs more than tablets.