jsnb,
Вариант renameID()
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<table id="test">
<tr><th>ID</th><th>Something</th><th>del</th></tr>
<tr><td>1</td><td>aaa</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
<tr><td>2</td><td>bbb</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
<tr><td>3</td><td>ccc</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
<tr><td>4</td><td>ddd</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
<tr><td>5</td><td>eee</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
<tr><td>6</td><td>ggg</td><td><a href="#" onclick="removeRow(this.parentNode)">del</a></td></tr>
</table>
<button onclick="renameID()">click</button>
<script>
function removeRow(td) {
var row = td.parentNode;
row.parentNode.removeChild(row);
}
function renameID() {
var tds = document.querySelectorAll('#test tr td:nth-child(1)');
for(var i = 0; i < tds.length; ) tds[i].innerHTML = ++i;
}
</script>
</body>
</html>