Wow, that's real interesting!! Thanks for going to the trouble of measuring it. I should google average table widths. I will do that now.
Edited to add - That was easy!
"Most dining tables average
36 inches wide and vary from
30 inches to
48 inches. A 72 inch long rectangular table will comfortably seat six. A 96 inch long rectangular table will comfortably seat eight. A
120 inch long rectangular table will comfortably seat ten."
http://www.wayfair.com/ideas-and-adv...ize-S4891.html
So who exactly is using these 15" tall table runner/placemat sets??