The History feature allows your session saved in a file when the Packet Window is closed and be restored the next time the Packet Window is opened. The history is saved in a text file named mlog.his in your XMLog folder.
To enable the history feature choose Options/Packet Options and Port Select, pick the Options tab, and enable the history Save option. Also set the history Lines value to the number of lines you want to save.
Choosing File/Clear Screen History will erase your saved history and clear the screen.