Thanks Greg - very informative.

As a practicing idiot, I make the following remark with a great deal of trepidation!

I think there's an oversite in your code.

Sorry!

I think
should be
and when executing the code in a document with three varyingly sized tables. the first two loops change Cells(1) to the new letters in each table, but the third loop only changes the Cells(1) in the first table.
Unfortunately I haven't yet grasped exactly what's going on, so if I'm right (which is by no means certain), I can't suggest a correction for the third loop.

Believe me, this is not a vanity comment.
I use sample code from Forums to help me to learn techniques and good practices, so if there IS a bug it would be helpful to future browsers to correct it, and if there ISN'T a bug, an explanation of why my my comments are wrong could prevent other people from making the same mistake.