Emacs: Command to Open Menu
- Alt+x
menu-bar-open
- Open the graphical user interface menu. Works in text terminal too. [see Emacs 24.4 (Released 2014-10)]

menu-bar-open
【F10】 in text terminal
Old Text Menu Command
Alternatively, you can also call the old command Alt+x tmm-menubar
【Alt+`】.

tmm-menubar
【Alt+`】 in text terminal.