Modifying WordPress (i.e. NOT site-specific) menus?

Hi! I’m pretty sure I don’t even have the right words to describe this question properly, so I’m hoping a picture will cover that inadequacy. Is there a way to change the contents of the menu pictured below (whatever it’s called)? I hardly ever need to access Themes, Widgets, or the Theme Customizer, but would find it really handy to have “one-click” access to Media, Pages, and Products. Can that be done? Thanks in advance!