|Don't do this.|
A smartphone camera is never going to approach a dedicated camera for capability or functionality. Image quality is always going to be better using a camera rather than using a phone. Even the daddy of all smartphone cameras - the massive 41mp Pureview sensor on the back of the Lumia 1020 can't compete with anything better than a mid-range compact. And that phone is far and away the best phone for taking pictures available today.
So why do we take billions of photos a day on our phones?
It's the old adage 'the best camera you have is the one you have with you' coming into play. We have our phones with us 24/7. They go everywhere and are always ready to grab that photo. Pocket to picture times are impressive and the phone is always in your pocket. The dedicated camera has become all but obsolete.
A tablet isn't something that we carry all the time, it isn't convenient, ubiquitous or even easy to use. You're highly unlikely to be carrying a tablet around instead of your smartphone so why not just use the phone to take the picture? And if you're going to carry around a second device for the purposes of taking photos you might as well go for a camera and realise the benefits of a device designed to take photos.
There is only one possible valid use case I can see for a tablet's rear facing camera, and that is for snapping a picture of a whiteboard or a flipchart in a meeting presentation. Even then I'd wager your phone still makes more sense.
So please, don't stand in front of landmarks or at the back of performances waving your tablet in the air trying to video or take photos. It might be big, but it's certainly not clever and everyone around you will mark you out as one of life's failures.