There are Excel templates in which only the work area is visible, and
everything outside the work area is gray. How is that done?
The unused rows and columns are hidden. For instance, if you wanted to
show only 10 columns and 50 rows, you could enter
K:IV
in the Name Box (on the Formula Bar), hit Return to select the columns,
then choose Format/Columns/Hide.
Similarly, entering
51:65536
in the Name Box, hitting Return, and choosing Format/Rows/Hide will hide
the unwanted rows.
Note that this will not prevent someone from scrolling (or using the
Name Box to select) outside that boundary. To do that requires using
event macros. Post back if you're interested.