Two files in folder ExtData appeared: what purpose they have?

Some weeks ago two files appeared in the folder ..\Garmin\ExtData on my Edge Explore (firmware 5.10), probably after synching through Garmin Express:
- 006-D0952-07.bin (38 KB)
- 006-D0952-08.bin (37 KB)

Somebody observed the same and maybe more important:
- what are these files and what is their purpose? Once there they remain in place.
- can or should they be deleted from the device, and if not, please explain why not so we can get some more insight?

Specially @aweatherall or @Garmin-Matthew have some clues?