When you want paragraph breaks in textarea, what you would do is just leave the empty lines within the textarea.
Then at the top html_record or html_record_long you would add:
$rec{'Description'} =~ s/\n/<BR>/g;
This would have to display the line breaks correctly when you display the record.
Find this and more in the FAQ noted below.
Unoffical DBMan FAQ
http://webmagic.hypermart.net/dbman/