Have you tried to log out/in from the app?
An educated guess:
The path tells you the name of the user account (email):
/home/blynk/data/[youremail]/
Taking one of my files as an example:
history_1250341282_v6_minute.bin
1250341282 is an ID for the profiles dashboard. It could be manually changed thru the admin pages or by editing the file [youremail].Blynk.user in the root path of Blynk. Probably not something I would recommend doing just for the fun of it!
v6 is virtual pin number 6.
I’m still curious about how the .bin files are formatted thou 