Here is what I am trying to achieve:

I have a large table whose cells either include much information or nothing
at all. Naturally, I don't want to display all the information in the table
because it gets too large. I want to mark all the cells having information
in them with an "R". As I click on any cell with an "R", the full content of
the cell is displayed in a large area on the top right on my spreadsheet. I
want every active "R" cell, to display its content in the same top right area.

How do I set this up?