OS X 10.10 or later. iTunes only allows one playlist to be selected at a time. This applet can perform common useful tasks on a multiple selection of playlists: rename (add text, remove text, search and replace text), duplicate, delete, export, merge.
Tools in the Rename tab operate on the selected playlists' names
(via in-app purchase)
Perhaps Also of Interest...
downloaded 9m 28s ago
Remove iTunes tracks disassociated from files
downloaded 9m 44s ago
Exports and then re-imports selected tracks' artwork
downloaded 13m 47s ago
List tracks common or exclusive to two playlists
downloaded 45m 26s ago
Finds and displays any empty folders in the iTunes Media folder
downloaded 46m 23s ago
Re-associate batch of dead tracks with files from selected folder
downloaded 55m 44s ago
Title Cap various track tags, featuring editable exceptions lists