Complex Excel spreadsheets usually contain a lot of important data linked by formulas and calculations. By saving an Excel table as read only, you automatically prevent unwanted changes to the content. Saving a spreadsheet in this manner is useful for sharing it with colleagues or external clients because at that stage you’ll probably want to avoid it being manipulated or accidentally edited. But even for your own purposes (e.g., for final calculations) making files in Excel read only can be useful.
By adding password protection to your read only Excel file, you control whether changes to your Excel table are permitted and who gets to make them (by sharing the password). It’s just as easy to remove Excel read only if you want to enable editing of your table again. The process is similar to removing read only for individual Excel worksheets or unlocking a Word document for editing.