枠線の基本(3×3)
<table border="1" width="500">
<tr>
<td>1</td><td>2</td><td>3</td>
</tr>
<tr>
<td>4</td><td>5</td><td>6</td>
</tr>
<tr>
<td>7</td><td>8</td><td>9</td>
</tr>
</table>
rowspan を使う
<table border="1" width="500">
<tr>
<td rowspan="2">1</td><td>2</td><td>3</td>
</tr>
<tr>
<td>4</td><td>5</td><td>6</td>
</tr>
<tr>
<td>7</td><td>8</td><td>9</td>
</tr>
</table>
<table border="1" width="500">
<tr>
<td rowspan="2">14</td><td>2</td><td>3</td>
</tr>
<tr>
<td>5</td><td>6</td>
</tr>
<tr>
<td>7</td><td>8</td><td>9</td>
</tr>
</table>
colspan を使う
<table border="1" width="500">
<tr>
<td rowspan="2">14</td><td>2</td><td>3</td>
</tr>
<tr>
<td colspan="2">5</td><td>6</td>
</tr>
<tr>
<td>7</td><td>8</td><td>9</td>
</tr>
</table>
<table border="1" width="500">
<tr>
<td rowspan="2">14</td><td>2</td><td>3</td>
</tr>
<tr>
<td colspan="2">56</td>
</tr>
<tr>
<td>7</td><td>8</td><td>9</td>
</tr>
</table>