Any list can be exported to a spreadsheet (.csv format).  From the list tab, scroll down or search for the list of interest.  Then select the  icon.  The list will be loaded onto your computer in a .csv format which can be opened using a spreadsheet program such as Microsoft Excel.

In addition, a list can be exported from the email track screen after an email was sent to that list.  This export spreadsheet contains the basic contact information but also contains performance information for that email send, such as opens, clicks, bounces, plays, and shares.  To download a list in this way, first send an email to the list.  Then select Track for that email (from the main email screen).  From the track screen, select the  icon.