This is why it is a very bad idea to built entire sites using tables, without any ids and classes.

Yes, you may start anywhere using preg_match, but if there are lots of unnamed table rows or cells (or divs for that sake), preg_match is probably not the best solution. If you insist on using regular expressions, then you should know that [\s]+ will match all spaces and line breaks, which is useful search for more than one line.