Reads custom table data that is stored inside of an object or the scene. Reads also custom table data for the application's currrent session. See also the other custom data block related functions.
objectHandle: handle of the object, or sim.handle_scene if the data is stored in the scene, or sim.handle_app if the data is stored in the application's current session.
tagName: a string that identifies the data.
Lua return values
tableData: the table data. Returns an empty table if the custom data is not present.