This cludge works! Thanks. For others . . .
FTP to your host, and find the directory containing your template.
Find file customjs.js, and open it.
After . . .
jQuery(document). ready({
Insert . . .
jQuery('table').addClass('table') ;
Now, my site tables look how I styled them in TT.
Kudos to marcin-sarewicz.
EDIT: I found that if I upload my template again, customjs.js is overwritten and my code edit is gone.
So I put this in Template Toaster itself.
Go to General > Javascript, and enter this code:
/********** Table Fix **********/
jQuery (document).ready
(function()
{
jQuery('table').addClass('table');
}
);