The cauldron symbolizes the goddess. When in use the cauldron symbolizes the womb because it holds something. When in use on an altar the cauldron represents the earth as it is a working tool used during ritual work. 
 
Uses of a cauldron:
Make herbal teas
Spell/ritual work
Place a candle inside to burn herbal blends during spell/ritual/wish work
Altar decor
Burn charcoal with resin incense
Incense cones
Making brews
 
This is an open pot/casserole dish style cauldron measuring approximately 11.2cm wide x 9cm high. Cast iron.