When you use the QBE or Mass Update buttons depending on what you intend doing, this opens up new TABS with the relevant information's showing
QBE : you can perform any complex query on the current Table to get subsets of your data (and save the QBE for future use)
Mass Update : you can select any column(s) of the current Table and then define an expression and a condition to use to update your data
Stored Queries : you can load any stored queries (QBE or Mass Updates - they ARE different) and apply them to the current table (only the current Table's queries are displayed)
If you want to reformat columns you must do it BEFORE entering this mode
In all of these screens you have a "Cancel" button to revert to the previous screen canceling any modifications done but still keeping in memory whatever you have already done.