The "Map" theme is designed to complement the Managed Locations addon and allows you to extend your JEvents menu items and modules with maps of the relevant event's locations/venues.  The layout allows you to display a map of locations before, after, or instead of the output from your component or latest events module.

In the JEvents config set the layout you want to appear alongside (or as a fallback to the map) on the Map layout config tab. You can also set the size of the maps here too.