A Tooltip

HTML

<table class="upgradeTables">
    <thead>
        <tr>
            <td>My head 1</td>
            <td>My head 2</td>
            <td>My head 3</td>
            <td>My head 4</td>
            <td>My head 5</td>
        </tr>
    </thead>
</table>

CSS

.upgradeTables {
    margin-top: 2em;
}
.upgradeTables td {
    position: relative;
}
.tooltip {
    background: #000;
    color: #f7f7f7;
    opacity: 0.95;
    display: block;
    font-weight: bold;
    position: absolute;
    text-align: center;
    top: -100%;
    left: 0;
    width: auto;
    min-width: 100px;
    padding: 5px;
    
}

JavaScript

$(function() {
    $('.upgradeTables td:gt(1)')
        .each(function() {
            var tooltip = document.createElement("div");
            $(tooltip).html('Upgrade To').addClass('tooltip').css('display', 'none');
            $(this).append(tooltip);
        })
        .hover(function() {
            $('.tooltip', this).toggle();
        });
});