In the gnome file explorer there's 3 different menus, marked only by generic icons, and I always forget the one to open a new tab.
The Main Menu offers global actions, and appears in the left-hand global pane of the window. The Current Folder Menu offers actions specifically related to the location named in the location bar. The View Options menu is part of a split button with the view switcher, and has additional view-related options.
You're right that the icons themselves do not explain their full and complete functionality. Fortunately, we do not need to rely on hoping for the right labels for actions (be they textual or iconographic). For software intended to be used on a regular basis, it's worth spending a bit of time internalizing the model.