You can download two types of files:
- Backup file
Backup files - it contains devices configuration and it is used to configure other router to the same configuration level as the device from which it was downloaded. https://wiki.teltonika-networks.com/view/RUT240_Configuration_Backup
Troubleshoot files - it also contains configuration of the device, but it cannot be used to configure other devices. Troubleshoot file is used to see routers activity and etc.
To open them, simply uses 7zip or WinRAR software and to view files notepad or notepad++ can be used. You don't need them to extract, simply open them by double-clicking and select the directory/files you want to view.