I think the question is a little deeper than that. If you look at the Application Security Line of code in the workbench, you'll see that on the same line there are "Y"s in the View, Add, Change, Delete Columns. These values are there regardless of whether or not there is a separate Action Security entry for that object. In fact, you can set Action Security to "N" across the board for that object and there will still be "Y"s in the same columns on the App Security line. I've never really figured out why either and never really cared enough to try and figure it out, but do know the developers use some of the same columns for different security types. For instance, OK/Select column is also used to store the Prompt for Data Selection, security setting, etc, etc...