Put a powerful cpu, gpu and an usb controller and there's no technical difference between a tablet and a console. Console games have only historically had different graphics and gameplay because of historical limitations of mobile hardware. Not because there's anything magically special about an xbox. You give mobile devices similar hardware and consoles become dumb pipes.
There is no technical difference between a laptop, console, desktop either. But who would want a tablet that is as thick as a laptop, with fans and 1 hour battery life.
You can't just stick a i7 and quadcore GPU in a tablet. Your iPad is good for casual games. People are playing lots of casual games but those games are unrelated to games like COD, Battlefield, Elder Scrolls, GTA, FIFA, Madden. It's like comparing a TV show to a big blockbuster movie.
