How do I get adobe digital editions on my Matricom G-tab?

You can't install ADE (digital editions) itself.

You can install an Adobe DRM compatible reader such as Bluefire, Aldiko or Overdrive.

You must then register the app with the same Adobe ID as you use for ADE on the computer,

and transfer books (DRM .epub/.pdf) files using USB connection and a file manager (Windows Explorer, Mac Finder) to the tablet as mounted drive.

I've found Bluefire most easy to get on with.

Some people have registration problems with Aldiko and Overdrive.

Overdrive can be the most convenient if you only want to use library books.