问如何防止表单元格在添加文本时调整大小

EN

<div>
   <table id="gametable">
        <tr><td>1</td> <td>2</td></tr>
        <tr><td>3</td> <td>4</td></tr>
        <tr><td>5</td> <td>6</td></tr>
    </table>
</div>

        #gameTable {
        table-layout:fixed;
        position:absolute;
        height:640px;
        width:640px;
        margin-left:31%;
        margin-top:8%;
        }

        div {
        white-space: nowrap;
        overflow: hidden;
        }


        td {
        cursor: pointer;
        background-color: rgb(150,150,150);
        box-shadow: 3px 3px 1px #888888;
        text-align:center;
        font-weight:bold;   
        padding:0px;
        }

        table.rows[x].cells[y].innerHTML = mines;