Here’s a small plugin that creates CSV out of a categorized chart. Included in the demo is a menu item in the Export menu that passes the CSV to a PHP script and returns a file to be viewed in Excel. Charts inside Excel are not supported in this demo.CaptainBli commented
Even though there hasn't been many comments recently, this would be something very useful. OpenXML and ClosedXML have ways of creating charts (that probably wouldn't be as good as yours) in xlsx as well as adding embedded images that could be exported with the series data.
If we added an option to pin the tooltip on click, we could easily add links inside it.