Yes, I've see this problem before. Google play just doesn't automatically work on all devices. Checking this list:http://support.google.com/googleplay/bin/answer.py?hl=en&answer=1727131
I do not see your RD101 number or Pandigital Novel (which is what I think you have).
So I think you are right. That you need to get something like CyanogenMod running on it and then load up the gapps application (I believe Google Play is part of this package). It looks like Pandigital is one of those sub $100 tablets. So I would expect lots of people putting CyanogenMod on it. But I haven't found much evidence of this. If you go out and get another tablet do check the CyanogenMod official and unofficial support list.
In the end, Android is Unix with Java running on top of it. Yes, I know, that's a very simple way of looking at it. But I just wanted to point out that if you are already familiar with Unix or a derivative of Unix you already know a lot about Android.
Just a thought. I am thinking this will not work. Mostly because your device is not on the list in the above URL. But you might try and installing the gapps for your version of Android just to see if it will work. If you follow any of the CyanogenMod install tutorials on line you will eventually come across the steps telling you where to find and how to pick out the correct version of gapps. But like I said, this is a long shot. Also, I have never tried this. For all I know this may make your tablet unusable.