Embed a new table
within the existing structure to create four columns on the right-hand side. Here is how the HTML code would appear:
<table class = "big first">
<tr>
<td class = "px10">Cell1</td>
<td class = "px20">Cell2</td>
<td class = "px30">Cell3</td>
<td>
<table class = "big">
<td>1</td><td>2</td><td>3</td><td>4</td>
</table>
</td>
</tr>
</table>
CSS:
.big {
width: 100%;
}
.first {
table-layout: fixed;
}
.big, .big td {
border: 1px solid black;
}
.big td {
background: rgb(0, 162, 232);
}
.big .px10 {
background: orange;
width: 10px;
}
.big .px20 {
background: green;
width: 20px;
}
.big .px30 {
background: yellow;
width: 30px;
}
View a demonstration here: click here.
Update: There may not be a necessity for an additional table
: alternate link.