Note: avoid greedy .* particularly in complex expressions, it's bound to cause you problems. Negative classes often work better. For example, instead of <td.*>, use <td[^>]*>.
As per Michael comment, your posted regex does not work. But even with the simplified regex:
hyperlinks = regexp(html, '(?<=<tr><td[^>]*>)<a.*?/a>', 'match')'
you can see that there is a problem. Unfortunately for you, the problem is actually the webpage which is actually not valid html. Your whole problem comes from the fact that the spacer.gif <a hyperlink (on line 131 of the source html) is never closed. So of course, your regex captures everything up to the next a> which belongs to the next <tr><td>.
Unfortunately that makes your life rather difficult. Try:
hyperlinks = regexp(html, '(?<=<tr><td[^>]*>)<a[^>]*>[^<]*</a>(?=</td><td[^>]*>\d+ hp</td>)', 'match')'
And if you can report to the website owner that their page is missing a closing tag.