[Klaus Linke]

1) Any idea why you can't search for end of cell characters?

No ... Seems just like some technical decision that was made way back in
Word 1 or 2 by the designers.
Probably it was just simpler to avoid the complexities that would arise.

2) Why does ^&% work?

When you search for a style or formatting in a table, Word matches the text
cell by cell.
^& in "Replace with" re-inserts the matched text... The only thing left to
do is to add the % sign, to get the result you want.

Thanks for the solution,

You're welcome!
Klaus