haha oh man, I've been trying to figure it out for AGES.
Seems that data_table_node never populates with anything. Some people in these issue queues are manually adding rows with phpMyAdmin, under the impression that this is the way to do it.
The two relationships appear in data table views, but they don't work because the data_table_node table is empty. Also, there's a weird block that becomes available, which contains a form of sorts, but this only causes errors if anything at all.
Anyone have any ideas? Can this be documented, or is it simply leftover from previous functionality?
Sorry, I'm just really confused! :)