You do not want to design an app with 200 checkbox fields, you the other's on the Community Forum will agree with your approach to make that a child table?
Have you tried making a Summary report? That is the 2nd choice when you go to make a report. The result will basically be identical to the Excel Pivot Table. Also, if you have any Concept where the 200 checkbox fields are grouped into categories, you ca have Dynamic filters on the report to just focus on certain of the columns as having a report that is 200 columns wide will not be very user friendly.
