The point of it…
You may well find you have got some entries which weren't what you expected. Suppose you have done a search for SHRIMP*/PRAWN* -- you may find a mention of Shrimpton in the listing. It's easy to clean up the listing by simply pressing Del on each unwanted line. (Do a sort on the search word first so as to get all the Shrimptons next to each other.) The line will turn a light grey colour.
Pressing Ins will restore it, if you make a mistake. To delete or restore ALL the lines from the current line to the bottom, press the grey - key or the grey + key by the numeric keypad. When you have finished marking unwanted lines, you can choose (Ctrl+Z or ) to zap the deleted lines.
If you're a teacher you may want to blank out the search words: to do so, press the spacebar. Pressing the spacebar again will restore it, so don't worry!