Importing projects in Fable Blockly is extremely easy!

Windows/Mac
Tap the file icon at the top left, then select the open project option. A file selection screen will open and all you have to do is find the project and open it.

Chromebook
Select the Open Project option. Then select the Import Project option. The Storage permission is required after this step, so make sure to grant it when the app asks for it.

iPad
The feature is not yet supported.