I assume you are talking about a freeform visual taskboard? The tasks on there are vtb_task records (private task) and you can query on that table. But since a vtb it is just a visualization of the tasks itself, I don't think you can see to what board they belong.
Question is: why do you want a list of records that are created on the Freeform board. The only reason to put them on the board, is because that's the way you want to work/visualize them.