Confession: I thought we didn’t need a tag browser a long time ago, hoping to minimize clutter on the sidebar. @danny disagreed but we did it my way, and I’ve since come to believe I was (probably) wrong. 
I’ve been thinking about some really cool ways to flesh out our tag functionality (partially based on feedback from @AndersVinberg in this thread) but for now I think @evand is right – since there’s no browser, you’ll need to make a bookmark if you want to navigate directly to a tag.