This is the problem. You don't have Linux x86 but Linux ARM. Adobe doesn't provide this version for download. Nokia is licensed to distribute it on the tablet. You have to rely on Nokia for publishing an update.

But sometimes this doesn't even help. Some very clever sites (or at least their web designers think they do it very clever) are too stupid to detect a Flash plugin on uncommon computer platforms, and simply refuse to offer the Flash content because their detection mechanism is so clever and error-free (or at least their clever web designers think so).
If you encounter such a site, chances are that you'll never be able to view it on the tablet, no matter how up-to-date your Flash plugin is.