Those are the sample files for Blender-VR. In the future they may be hosted separately since their size tend to grow.
Git is not a good system to work on binary files, so it's recommended to use the SVN protocol to interact with this repository instead.
svn checkout https://github.com/BlenderVR/samples/trunk
Or for an individual sample folder:
svn checkout https://github.com/BlenderVR/samples/trunk/basic