If you create 2 configs one with all the features unsuppressed and the second with all the ones you want to manipulate in the design table suppressed and then create your design table it will automatically populate the columns and the suppression states. then you can add the needed configs at will from the design table. This way you don't have typos.
Another way to prevent typos is to do it the normal way by double clicking on whatever feature or dimension you want added to the design table. Why would you want to type the header info into the design table?
Search the help for "summary of design table parameters" to get an overview of what is possible with design tables and how to do it. You'd think the tutorial would point people to this for further study.