Exporting an Excel Spreadsheet containing a pivot table and charts to MySQL
It's possible, but it will take some work.  "Unpivoting" sounds like part of the task.

I would dump everything in .csv files, then LOAD DATA them into MySQL into tables that mimic the spreadsheet sheets.

Then, I would construct the tables that make more sense in the database.  An example is the unpivoted version of the data that is spread across 90 columns.

Then I would write various INSERT ... SELECT ... statements to copy the data from the Excel-centric layout to the MySQL-centric schema.  It is the sort of thing where errors are quickly rectified by DROPping the new tables and rerunning the conversion queries.  Plan on doing that a lot until you get the tables looking good.

Then, write and run queries to use the data in the database-centric format.  You should try writing the queries earlier to get a feel for what you will be getting into.