This is for the HBO and Channel 4 animated series, of course, that premiered in 2010, and not the audio series.
The only available information for the opening and closing theme song (same) of The Ricky Gervais Show is its composer. The song was composed by a certain Glyn Hughes, who also happens to be one of the many producers of the show. As for his musical resume, he also did some work for another Ricky Gervais show—Extras—and one episode of The Office.
The song remains untitled as of the moment, you can just unofficially refer to it as “Theme from The Ricky Gervais Show” or something to that extent. It also remains unreleased, and there are no official soundtracks (or the like) whatsoever. So your best bet would be just to go back here and relive the theme as often as you’d like. Will update this post if Mr. Hughes decides to release a full version.
I guess that is it for this one. Below are the opening and closing credits so you can listen to happy-sounding tune.