I have widows 8.1 pro 64-bit machine, with windows sdk 8.1 installed on it, along with emulator and vs2013 express.
I am creating apps and run them on emulator, which emulates following devices:
How to add more devices here. How to emulate windows tablet using this emulator?
If you have a WP8.1 project, you will only get phones for deploying/emulation. Make an universal app or a separate windows8.1 project to deploy / test your code in the Win8.1 simulator.
UniversalApplications seem to be your solution here, hence you want to target both, phone and tablet/windows-store apps.