Once https://gerrit.wikimedia.org/r/#/c/265660/ is merged, since before that table copy/paste isn't really a thing.

View the tables demo page, and pay attention to the alien table. Specifically, copy something including an alien part of the table and try to paste it. Errors such as this will occur:

[Error] Error: Cannot set attributes to non-element data
	newFromAttributeChanges
	importTable
	afterPaste
	(anonymous function)