A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Your issue isn't unrelated but it is decidedly different from the message you replied to. Unfortunately, it still falls under the same general explanation that OLE in Mac Office is very limited...
Yes, you can edit the content being displayed in the Excel sheet [change values, edit formulas, format cells differently, etc.] but you cannot modify the object itself. IOW, the number of Columns & Rows is fixed when the object is created -- Neither can be increased or decreased in the Mac version of PPT. If you need to change number of cells you need to replace the current object with a new one... Or make the revision using a Windows version of PPT.