"What is the purpose of the despatch box? How did the name come about? Thanks for your time!"

In the House of Representatives there are two despatch boxes that sit on the central table. Ministers and shadow ministers stand at the despatch boxes when they speak in the chamber. They were called despatch boxes because traditionally they were used to transport despatches or documents. 

More information about the despatch boxes can be found here.

diagram to help explain What is the purpose of the despatch box? How did the name come about? Thanks for your time!