If you go to Settings -> Addresses and scroll down to the bottom, you’ll see Imported Addresses with the option to Transfer All on the right.
Transfer All will allow you to transfer the total balance of your imported addresses in one step.
Spendable Addresses are addresses you’ve imported that include the private key and you can spend. Watch-only Addresses are addresses you’ve imported that don’t include the private key. In order to spend from Watch-only addresses, you need to make sure you have the private key.