Your XPath expression does not match the input, so I'm surprised you're getting a result anyway. From what you stated in the comments, in seems that for some reason it returns elements of both the table header and body elements (which it shouldn't query at all).
For getting the third table cell of the first row in (each) table body, use this query:
//table[@id='specialHandlingSelectionTable']/tbody/tr[1]/tr[3]
If there are multiple table body elements, and you only want to query the first row of all of them:
(//table[@id='specialHandlingSelectionTable']/tbody/tr)[1]/tr[3]
If you want to query the table headers instead, replace tbody
by theader
.