I made the same analisys.
Conclusions are:
13,3" 16:10 display is 29,44cm x 16,56 cm
12,0" 3:2 is 25,36 x 16,91cm
so Surface has a taller display.
On Surface, with Excel 2013:
100% size ratio: with menu of XL, you can see until cell V35
without menu of XL until cell V39
150%: with menu until...