You take your tablet (a slab of wood) and you warm it some by the fire.

You melt your wax in a ceramic cup and pour the wax onto the level surface of the tablet.

If the tablet has a slightly raised edge then you should get a covering of wax that is almost as thick as the lip (wax shrinks a lot when it cools so the surface will not be exactly flat but that should not matter much.

they used a wax tablet

The Greeks were the first to use wax tablets for writing in the mid 8th century. However, many ancient civilizations used wax tablets.

Stilus (sharp piece of wood shaped like a pen)

wax tablet

The wax tablet and stylus was used for writing by the Romans They would inscribe their message or note on the wax with the stylus. The message could be erased by scraping or melting out. This was ideal for children learning their writing or someone wanting to make a quick note without using expensive papyrus.