<style>
        td {
            border: 1px solid #000; 
            text-align: center;
            vertical-align: middle;
        }
        th, td {
            padding: 8px; 
        }
    </style>
    
        <table class="table">
            <tbody>
                <tr class="d-none d-lg-table-row">
                    <td>1</td>
                    <td>2</td>
                    <td>3</td>
                    <td>4</td>
                    <td>5</td>
                    <td>6</td>
                    <td>7</td>
                </tr>
                <tr class="d-lg-none">
                    <td rowspan="2">1</td>
                    <td>2</td>
                    <td>4</td>
                    <td>6</td>
                </tr>
                <tr class="d-lg-none">
                    <td rowspan="2">3</td>
                    <td>5</td>
                    <td>7</td>
                </tr>
              
            </tbody>
        </table>