I know Android is built on linux but I'm not too sure of the actually functionality of it.

I have one of the humble bundles and there (edited, wrong 'there' :/) are a few linux versions available, would these run on an Android phone or tablet?

Not without modification, no.

Android only runs Java (Dalvik, specifically) executables, which may then load libraries compiled natively (such as stuff written in C or C++) - this is how GemRB runs on Android, it doesn't run directly but is loaded through a small Java application (completely invisibly behind the scenes to the user).

If you know Java and whatever language the games are written in (I'm guessing you don't, since you ask), as well as having the source code (some Humble Bundle games has had their source code released), you might, with some work, be able to port the game(s) to Android.

Ah well :(

Thank for the answer

I believe it was Nokia who released a phone, the N900 I think running some Linux variant.
It never really caught on, but it could in fact compile and run a lot of linux/qt based code if I recall.

The problem of course being that just because it could run on the phone didn't mean it was running smoothly or usably. There wouldn't be much thought of in the smaller screens, resolutions or lack of a mouse. Sure you could compile and run stuff like ScummVM or Dosbox or Transport Tycoon Deluxe and even Quake 3 without much trouble, but for example Quake 3 kinda expected you to have a mouse and keyboard, and while the slide out keyboard was okay, try doing mouselook and figure out how to left and right click quickly enough ;-)

Agreed, I normally play Quake 1 on nightmare but on my Android w/ keyboard, easy is extremely challenging. Getting good input devices built into something designed to fit your pocket seems very difficult. :(