You have a number of options for downloading folders (including all files and child folders contained therein).
Downloading an Individual Folder
Select the drop down arrow next to "Edit and click "Download"
Batch Downloading Multiple Folders
Select the checkbox for desired folders, click "Download" at the top of the table.
To download a file, select the checkbox for the desired file, click "Download" at the top of the table.
Select the checkbox for desired files, click "Download" at the top of the table.
When downloading an individual file, the maximum file size is 5GB (the maximum file size that can be uploaded).
When downloading multiple files, the maximum combined total of all files being downloaded is 250MB.