This is the Slice Lookup code name editor.

Here you can define names that can be assigned to your slices. Each line on the screen aside from "Previous Menu" is a lookup code name. Initially they are all blank.

A slice only needs a lookup code name if you want to be able to use the "lookup slice" plotscripting command to get a handle to the slice.

The names you define here will be exported in your HSI file.