Flat surface items

"Flat surface items" refers to two similar groups of placed furniture items.

Items on which other items can be placed
"Flat surface items" sometimes refer to these items, which have flat surfaces that can support the placement of other items, and will work to create a Placed Bottle crafting station:

Items qualifying for a House flat-surface requirement
These items fulfill the Flat Surface Item requirement for Houses, even though some of them do not actually have flat surfaces where other items can be placed: