In Pro/E 2001 (2001320) Drawing mode, this "Pick Many" Mapkey still works - you can draw a box around many dimensions and modify their properties all at once (tolerances, text style, etc).
It must be choosing commands that still exist "behind the scenes", although it may be disabled in later builds of Pro/E?
BTW - I first saw the suggestion for this mapkey on the pro-user email exploder - there's a lot more Pro/E tips available there...
Ed