If you are using the default Litecoin-Qt client, you can use the 'export' feature of the client to automatically populate your list of LTC addresses using your existing address labels. Any invalid or duplicated addresses will be skipped.
Open your Litecoin-Qt client, and open the "Receive coins" tab.
Click the "Export" button and save this CSV file to your computer.
Once this CSV file has been exported, select the "Browse..." button on the "Upload CSV" tab on the add LTC Addresses page to locate and upload this file to CryptFolio.
Is it safe to provide CryptFolio a Litecoin-Qt CSV file?
The Litecoin-Qt client will only export your public Litecoin addresses. These addresses can only be used to retrieve address balances; it is not possible to perform transactions using a public address.