Looking at your screenshot, perhaps what you are looking for is "map channels, merge same names". That will get rid of lots of your duplicates by merging your nine Channel 4s and numerous Channel4+1s. This will then leave you with fewer channels you need to manually disable.
Perhaps also take a look at the bouquet tab. I don't use it, but I know people tick the one box for their region and have it automatically map only the channels from that region so you only get Yorkshire or London channels, avoiding the other regions channels.
You probably need to delete your existing channels first before doing either of the above.