The 17 inch method has been the standard even for an auspicious document pouch.
Warmest Regards,
Cecil
Further to what I had mentioned;
For the surface area of your `Feng Shui friendly' tables or for anyone wanting to manufacture Feng Shui friendly tables can use this explanation:-
(One Feng Shui foot is nearly equal to an imperial foot. One Feng Shui foot is roughly equal to 43 cms.)
Description of tables with multiples of 17 inches (lenght x width):-
THE MAGICAL 17 INCH FACTOR