Private chest is a lockable container. It can store up to 18 item stacks.
It can not be removed in 0.79.10 version.
How to build a private chest Edit
You need to a workbench near in order to place it down.
- Select Hammer that in your inventory
- Press [F] to switch to [Furniture] tab
- Press [Q/E] to switch to private chest
- Press [LMB] to place it down