Why not? PWRficient and Xmos are low power chips, xmos is used in a few expansions gadgets for the iphone. So you say it as a joke but technically is not impossible,
It was very low power in it's day but tablets are something else altogether. They require much lower power and PWRficient is well above that level.
It could probably be done but you'd have to reduce the frequency by a hefty margin and cut the memory speed right down. You'd probably still need a big battery and a fan though.
The processors on the Sam boards are much more suitable for tablets.
