freekyfrogy -- don't want to speculate about why you need to do this but let me just say I've been there.

First of all, I think the package for the browser is "osso-browser".

Another option might be to use iptables (which I've seen mentions of being an option on the tablet) to drop all connections to port 80 (i.e. HTTP connections). This could potentially break some of the stuff you do want to do, though.