Answer 1

Check www.w3school.com:
https://www.sololearn.com/learn/HTML/1033/

To make a cell span more than one column, use the colspan attribute:

Example:
<table style="width:80%" border="2>
<tr>
<th>Name</th>
<th colspan="2">Telephone</th>
</tr>
<tr>
<td>Hello world</td>
<td>123456789</td>
<td>098877554</td>
</tr>
</table>

Cells that Span Many Rows
To make a cell span more than one row, use the rowspan attribute:

Example
<table border="2" style="width:80%">
<tr>
<th>Name:</th>
<td>Hello World</td>
</tr>
<tr>
<th rowspan="2">Telephone:</th>
<td>123456789</td>
</tr>
<tr>
<td>987655432</td>
</tr>
</table>