Aligning table columns

Aligning table columns

I have a page with multiple tables in one zone. The issue is that each table has multiple columns but they are not aligned properly one below the other. 

I tried the following code but it did not work.

$("#rightDiv table tbody tr:nth-child(2) td:nth-child(2) table[name=Name]").css("width","300px");
$("#rightDiv table tbody tr:nth-child(2) td:nth-child(2) table[name=Modified]").css("width","300px");

The tables that I want to target are inside a div id 'righDiv' with the following structure.

<div id="rightDiv">
<table>
<tbody>
<tr><td>Some content here</td></tr>
<tr>
<td>Some content here</td>
<td>
<table>
<tr>
<td>Name</td>
<td>Modified</td>
</td>
</tr>
--- additional rows here ---
</table>
<table>
<tr>
<td>Name</td>
<td>Modified</td>
</td>
</tr>
--- additional rows here ---
</table>
<table>
<tr>
<td>Name</td>
<td>Modified</td>
</td>
</tr>
--- additional rows here ---
</table>
</td>
</tr>
</tbody>
</table>