1st, it's nice to see, ppl are still buying Touchpads.
2nd, I hope you all realize, this is a discontinued device which has no official support anymore.
Ok, that settled I would recommend to tell exactly, where the problem lies and read exactly, what the people write as a suggested solution.
So if you speak about opening a certain file (i.e. PDF) from an external source (webpage) or from a mail, there is always the oportunity to SAVE the file to your device. How this works, has been described in this thread before, so I won't elaborate again.
With the file on the device you have to either find a software which can open it (for PDF there is the standard adobe reader or kingsoft office) or copy it to your pc (via USB, via mail, via Dropbox or whatever) and open it there.
Well, now you've got your options listed and need not be all grumpy about this problem anymore.
Be happy, that a device, that was discontinued in 2011 still works for you.