You have to download the QPair app to the phone from the Google Play store. Once the app is run on both devices and they are paired, the tablet is supposed to be able to toggle the Wi-Fi hotspot on and off for the phone. So you can leave the Wi-Fi hotspot turned off on the phone and leave the phone in your pocket or bag. When the tablet need Internet access, you flip a switch in QPair on the tablet and it turns the phone hotspot on. When you are done, you can toggle it back off.
My G Pro is from AT&T and is running the stock AT&T ROM. It's rooted and I've applied the patch to enable tethering. When I pair the phone and tablet with QPair is says the phone does not support Internet via phone because of a carrier policy or device incompatibility. My guess would be an AT&T carrier policy is blocking it.
Has anyone else tried QPair on the Optimus G Pro? This should work with any Android tablet and phone if you download it from Play store. I'm wondering if I'll need to flash my phone with a non-AT&T ROM to make it work.