Sam,

          Have you tried setting a heading row (for the columns beneath it) and/or a heading column (for the row to the right of it) in Excel itself?  I have found that this tends to work, and across screen readers, better than doing said definition via the screen reader itself.

           This can be done whether or not one is using an actual table in a spreadsheet or not.

--

Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363  

Science has become just another voice in the room; it has lost its platform.  Now, you simply declare your own truth.

      ~ Dr. Paul A. Offit, in New York Times article, How Anti-Vaccine Sentiment Took Hold in the United States, September 23, 2019