Click + ADD BASE at the top of the Bases listing page, where all the bases in your workspace appear.
Choose Import from the dropdown menu.
From the pop-up menu that appears, choose URL.
Copy the direct download link and paste it in the box given. Click Import.
All the tables and fields from your files will then be listed in the pop-up window. Just customize your data, click IMPORT in the top-right corner of the pop-up window, and you're all set!