D3: Creating a table

Dear FCC community:

I want to create a table but for some reason out of nowhere a th-tag got added before the tds in the thead.
I want the first square before the a to dissappear. My code looks like the following.

<!DOCTYPE html>
<html lang="en">
<head>
    <script src="https://d3js.org/d3.v5.min.js"></script>
    <meta charset="UTF-8">
    <title>Midterm</title>
    <style>

        td, th {
            padding: 2px 4px;
            border: 1px black solid;
        }
    </style>
</head>
<body>
<table id="table">

    <thead>
    <th>
        <td>a</td>
        <td>b</td>
        <td>c</td>
    </th>
    </thead>
    <tbody></tbody>
</table>

<script>

    let data = [{a:1, b:3, c:5}, {b:4, c:6}];
    let keys = ['a','b','c'];
    let table = d3.select("#table");


    let body = table.select('tbody');
    let row = body.selectAll('tr')
        .data(data);



    let cell = row.enter().append("tr").selectAll('td')
        .data(function(row){
            return keys.map(function(column){
                return {
                    column: column, value: row[column]
                }
            });
        }).enter()
        .append("td")
        .text(function(d,i){
            return d.value;
        });



</script>
</body>
</html>

I hope someone can please help out.