Alt+F is a keyboard shortcut often used to open the file menu or file tab depending on the program you're using.
How to use the Alt+F keyboard shortcut
Alt+F in Excel and other spreadsheet programs
Alt+F in Microsoft PowerPoint
Alt+F in Word and other word processors
Using Alt+F in an Internet browser
Most Internet browsers (e.g., Chrome, Firefox, Opera) pressing Alt+F opens the file menu or the menu depending on the browser you're using.
It's possible for a web page to use this shortcut to open its file menu instead of the browser menu. If pressing this shortcut opens a file menu in the web page visit a different web page.
Related keyboard shortcuts and keys
Below are links to related keyboard shortcuts and individual key pages.