After starting the game, If you hit F5 to get to the launcher then click 'Help' from the options there, you can see a list of controls and keyboard shortcuts to save and load also.
Besides manually saving/loading through the launcher as you've mentioned, the game also uses autosaves every so often. I think by default it's every 5 min, but that can be adjusted from somewhere within the Scummvm launcher.
Keyboard shortcuts are also available: Press the 'Alt' key simultaneously with 0-9 to "Save game state 1-10".
To load the game, it's the 'Ctrl' key pressed with a key from 0-9 to load the corresponding save slot..
Personally, I prefer doing it the - F5, then click save - way, because with keyboard shortcuts it's very easy to slip-up and accidentally load instead of saving or overwrite the wrong slots if you're not careful. I don't trust myself, so I do it the long way :D
Post edited March 08, 2017 by RetroCodger426