I've had problems using peek in situations like this. Can't really remember why but I've used fieldvalue instead successfully.
Something like this:
let noOfRows = noOfRows('URLS');
for i=1 to $(noOfRows)
let v_url = fieldvalue('URL', $(i));
LOAD [Age:] as [Age]
(html, unicode, embedded labels, table is @4);
Note that fieldvalue returns the value from the field itself, not the value on a specific row within the table.
If you have duplicate values in the URL field you won't get the expected result.
I've solved this by adding a rownumber to the URL field to create unique values and then remove the rownumber when reading from the url.