Data file used by Tablaeu Desktop, a whiteboard visualization and analysis application; contains data extracted from an external data source, such as a Microsoft Excel workbook, Microsoft Access database, or a .CSV file; can also be extracted from a remotely connected data source. TDE files are used for storing external data in a format recognized by the Tableau software. They are useful for keeping local copies of data so that the data does not have to be reimported from the external source again.