What's the best way to export the data contained in the Root View table in Cube?
Unlike most element tables, there isn't a right click context menu option to copy or export table.
In the right-click menu > Actions > Export... you can export the elements to csv.
https://docs.dataminer.services/user-guide/Basic_Functionality/Elements/Working_with_elements/Importing_and_exporting_elements.html?q=export%20csv
In the training video's you can also find more information. See below link (starting at 35min 55sec in the video)
https://community.dataminer.services/courses/dataminer-administrator/lessons/elements/