Testing on real devices is very important. Especially for games.
Deploying your Unity app on your WinRT tablet is relatively comfortable with VS 2012.
– download Remote Tools for Visual Studio 2012 (ARM)
– install it on WinRT
– start the Remote Debugger on the tablet
– create a simple test project in Unity
– choose ‘Windows Store Apps’ in Unity’s build dialog
– open the project in Visual Studio 2012
– choose ‘Remote Machine’
– get a developer license for Windows RT on the tablet
Here is the screencast with instructions on how to deploy your app to WinRT: