No. But you should be able to delete it via Windows Explorer, maps will be in the Garmin folder.
look for files with the .img suffix in the Garmin folder. One of them is the map you want to delete. You could try renaming each file from .img to .omg till you find the unwanted map has disappeared. Now change the other files back to .img. And don't forget to look on the Garmin folder of the sd card .
It generally isn't. That map is the base map. What files are listed in the Garmin folder?