I've opened VOB files in studio by simply instructing the file brower to view "all files" and not just video files.  Of course, VOB files ARE video, just MPEG2 by a different name, but Studio (and some other NLEs) don't automatically recognize them as such.  One can also change the file suffix to 'MPG" and achieve the same thing.

If the VOB is big, Studio may break it into scenes as it imports.  If the first scene is under 1 second (perhaps triggered by static or distortion near the start of the file, it may refuse to import it.  The alternative would be to play or stream the file and capture into Studio.