Wallets can be dragged from the KWallet Manager window. This allows you to drag the wallet to a file browser window, where you can choose to copy, move, or link the wallet, as desired.
You might use this to save a wallet to portable media, such as a USB keychain, so that you can take your passwords with you to work or on a vacation, and still have easy access to important sites.
Future versions will have built-in functions for easy export or copying of data to portable devices.
Information on the internal structure of KWallet and some useful links to the code where you can find the answers on questions about the structure of the passwords records and the ciphers applied to keep passwords confident can be found on KWallet TechBase page.