When you create a Microsoft Excel PivotTable with a Datasheet view, Excel creates a query the data in the Datasheet view, and then create a PivotTable based on the queried data.
Excel exports the Datasheet view as a Web query file.
If Excel is running when you click Create Excel PivotTable Report, you are given the option to import the data in the Web query file into an existing worksheet, a new worksheet or a new workbook. Otherwise, Excel opens and imports the Datasheet into a new workbook. The imported data is displayed as a list in a worksheet and links the data with the information in SharePoint Foundation 2010. In Excel, the PivotTable field list and the PivotTable toolbar are displayed and you are prompted to create a PivotTable.