Sorry I didn't understand the question. From what I little I know, the only thing you can do with a TableMatrix is use the -selectcommand to pop a toplevel window with the cell's data into a text widget for editing. Maybe a smarter monk might know a way.

I'm not really a human, but I play one on earth. ..... an animated JAPH

In reply to Re^3: Tk TableMatrix format part of cell by zentara
in thread Tk TableMatrix format part of cell by IB2017

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":