How do I disable/enable combination keyboard shortcuts like alt+space and alt+F10).
Alt+Space by default is used to Activate the window menu
Alt+F10 by default is used for Toggle maximization state
You can change or disable these shortcuts in System Settings.
In Ubuntu 17.10 Desktop:
To disable these shortcuts, just click on one of them and press the backspace key.
For Ubuntu 16.04 the solution is same, but there is no defined default shortcut for Alt+F10