why do you think that certain areas of the caves have been given names such as the drawing room

I think people and kids would have used the caves for various purposes in the past and given certain ones colorful names.

They tripped along the murky aisles with the rest of the company, visiting the familiar wonders of the cave--wonders dubbed with rather over-descriptive names, such as "The Drawing-Room," "The Cathedral," "Aladdin's Palace," and so on.