I just tried google and facebook on both my N800 and N810 and it loaded in about 5 - 10 seconds without any problems at all.

Either there's something wrong with your tablet, or you have some settings that need altering, or there's something wrong with the connection itself.

Whatever the problem, your experience with the tablet is definitely not typical.

Did you try closing and reopening the browser after you switched Fit Width To View off?

Can you get ANY websites to load normally?

Are you running any applications in the background while you're using the browser?

Did you update the firmware and reformat the internal 2GB memory card before using the N810?

Regarding a reset, IMHO the best way to do that is to reinstall the firmware. If you've already downloaded the firmware the reinstallation shouldn't take too long.