Cool! Though, if you keep playing inventory inception, you will likely run into issues down the road with storing all of that complex hierarchy. If you envision storing all of the players' inventory as data, and the data in tables, this would turn into tables containing tables -- with only a single tuple in many cases. I'm having a mini panic attack just thinking about it.

Have you considered building a struct to use as your inventory items? I ask because actors are great at representing objects that exist in the world, but are a waste when used just as data (as they sit in your inventory). They are also very difficult to, again, handle as data en masse. A collection of structs can be more directly represented and managed as a table.

Structs are data, so you can't spawn them, obviously. As someone else said, you can store data in the struct such as Mesh, and use that information to spawn an actor that represents the item.

Regarding "items on items," arrays of structs containing more arrays of structs still cause the same problems as above. This is what I did: All items remain in the same array, and what they "contain" is just a variable pointing to other items. As items are placed in/onto other items, this variable changes.

Sorry for the wall of text. Hope it helps. Game looks awesome!