Context Menu (Right Click) keyboard shortcut in Mac OS X

After doing extensive research on this topic, I can confirm that there is no built-in mechanism that enables context menu either by direct shortcut or right mouse click simulation. This is due to technical limitations of the operating system, which prevents from determining coordinates of the current selection (e.g., selected element).

Fortunately, in some applications it is possible to use Apple Script to facilitate such action, but this is a strictly application-specific approach.

While the contextual activation is lacking, in OS X you can activate and access the top menu bar using the keyboard, which will give you access to all of the commands in the contextual menu, and more

http://www.cnet.com/news/access-menus-via-the-keyboard-in-os-x/

User vitor on the Alfred forums wrote this AppleScript which works in Finder on Catalina:

tell application "System Events" to set frontApp to name of first process whose frontmost is true

if (frontApp = "Finder") then
    tell application "System Events"
        tell application process "Finder"
            set _selection to value of attribute "AXFocusedUIElement"
            tell _selection to perform action "AXShowMenu"
        end tell
    end tell
end if

You can save it as a service and set it to activate with a keyboard shortcut.

It appears that every post I can find online is either wrong or merely outdated.

In Catalina, you can use System preferences -> Accessibility --> Pointer Control --> Alternate Control methods --> check Enable alternate control methods.

You can reassign the shortcut by clicking on the corresponding options button.

Update by another writer: here is that Dialog Box: this is brilliantly useful for me!

F12 brings up the context menu very close to the cursor (though not precisely as in Windows). This is great.

Some applications such as Power BI on a browser will use the combination Shift + F10