The file that is saved using Write to Spreadsheet file is a very simple file which can be opened by excel.
It is so simple, in fact, that it can be opened using notepad.
It is basically just the data with a seperator (the tab character by default) between each two values and a CR (enter) character at the end of each line.
Just right click the file, select "open with..." and select excel.
Or you can drag it into excel.
Or you can select "open" in excel and open it.
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