I'm frequently in the position of needing to analyze data in Excel that is in the form of cross-tabs.
This usually results from someone extracting data using one of the "Big-BI" tools into Excel.

I've worked out a way to get the Excel data into row-structured data in a csv file, but it's not very tidy and requires some data munging and scripting.

It seems that Tableau ought to be able to recognize cross-tab data, since it's simply the logical inverse of asking Tableau to provide the cross-tab for data in an existing visualization.