..after recently buying an Android tablet and setting up a gmail account i seem to be getting junk text messages...is that anything to do with google/android ?
I don't give my mobile number to anyone but family and close friends....
Just thought it was strange .....

For all intents and purposes, Google don't know what your phone number is, so it's nothing to do with them. Do you have an Android phone too? There's a slim possibility you've installed a dodgy app on that - failing that, it's probably just coincidink.

I've only ever used these on my mobile but

lookout ad network detector is good for identifying apps that spam notification crap

Postman SMS Blocker Is good for avoiding spam text messages