You can search in Excel with the Search Sheet bar, and use Find and Replace to swap out terms or values. Here's how to do it.
Combining Ctrl + Shift + Arrow keys lets you extend your selection in any direction until Excel hits a blank cell. Start from the top-left corner of your data, try Ctrl + Shift + Right Arrow, then ...
To apply data validation rules to a selected cell or range, head to the "Data" tab on the ribbon, and click the top half of ...