We have Flight Logs, and debug Logs (the ones you send with Bug Report). To which type are you referring?
For Flight Logs, we provide in-app ability to delete these.
For the Debug Logs, we auto-clean those up over time, allowing only the most 200 to exist. For ADSB logs, we only permit about a dozen of those to exist. So these continually delete the oldest logs when it fills up. If you want to do this manually, and have elected to storage your data on "Removable SDCard", then you should be able to delete them from a file manager (look for #Logs/ folder).