can you tell us more about reading browser history and how its stored etc
Discussion
it is not stored at all, it is not even accessed (see the code)
but just because these extensions provide functionality (NIP07) to the websites you visit the extension "knows" which that you visited these websites.
What matters is that these extensions are client side applications and don't share data - (not like many browsers that save the browsing history to a google profile for example)
you can also limit this further and enable extensions only on specific websites (though the extension software still needs to "know" that you visit these websites :) otherwise they can not provide the functionality.
thats great!