Huge geoCache attribute in a chart xml file

Hello everyone.

Recently I have started working with map charts as detailed in the microsoft tutorial web page: 

https://support.microsoft.com/en-us/office/create-a-map-chart-in-excel-f2cfed55-d622-42cd-8ec9-ec8a358b593b

I have noticed that the files created using this method, INCLUDING the downloadable example from the page I referenced above - have huge base64 included <binary> objects, that seem to be base64 of some unknown format.

I would love to know what these blobs represent, how can i interpret them using say another program or application, and I would also love to know if deleting them has any effect on the resulting file, seeing as these blobs are rather huge.