I have a book on "human factors" it contains a lot of good information on heights of tools, tables, cabinets, reach, widths, you name it This is used when doing designs of almost anything. The library near you might have a copy, if for no other reason then to see what all is inside. It is a "big" book so a lot to see. Now if someone is still interested in this sort of thing my personal copy is boxes up somewhere but I would be willing to get it out and see what it says about router tables, but you will have to ask nicely.
Ed