<table>
<tr><td>1</td><td>значение-1</td></tr>
<tr><td>2</td><td>значение-2</td></tr>
<tr><td>3</td><td>значение-3</td></tr>
<tr><td>4</td><td>значение-4</td></tr>
<tr><td>...</td><td>...</td></tr>
</table>
var values = [];
$('table td:nth-child(2)').each(function(){
values.push($(this).text());
});
var $cells = $('table td:nth-child(2)'),
values = [],
i;
for (i = 0; i <= $cells.length; i++) {
values.push($cells.eq(i).text());
}
$.each( $("#mytable tr"), function(index, val) {
var _text = val.text();
});