Since MyEtherWallet is an ERC-20 based wallet, you will be able to load all of your coins at once with one public address.
Step-by-Step Instructions to Import MyEtherWallet:
Step 1: Find your MEW public receive address in your MEW account.
Step 2: Copy your address and go to ZenLedger. Navigate to the Imports tab at the top of the screen.
Step 3: Search for MyEtherWallet.
Step 4: Select Ethereum (ETH) from the Select a Blockchain drop-down menu and then enter your MEW public receive address in the Public Address box.
Step 6: Click Import and all of your transactions will be imported into ZenLedger.
For a video walk-through of how to add a wallet address to your ZenLedger account, please check out our Wallet Import Article.