Introductory Physics Question?

We are analyzing the simple experiment where a tablecloth is quickly whisked out from under a set table to illustrate inertia. The question is, why is it important to pull slightly downward on the tablecloth rather than upward. Now, common sense tells me that pulling upward will tip over the objects on the table, while pulling downward doesn't affect the vertical position of the objects. I don't know, however, if this is the answer the book is looking for, it seems too obvious.