Use table-layout:fixed
in the table and word-wrap:break-word
in the td.
See this example:
<html>
<head>
<style>
table {border-collapse:collapse; table-layout:fixed; width:310px;}
table td {border:solid 1px #fab; width:100px; word-wrap:break-word;}
</style>
</head>
<body>
<table>
<tr>
<td>1</td>
<td>Lorem Ipsum</td>
<td>Lorem Ipsum is simply dummy text of the printing and typesetting industry. </td>
</tr>
<tr>
<td>2</td>
<td>LoremIpsumhasbeentheindustry'sstandarddummytexteversincethe1500s,whenanunknown</td>
<td>Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.</td>
</tr>
<tr>
<td>3</td>
<td></td>
<td>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna...</td>
</tr>
</table>
</body>
</html>
DEMO:
table {border-collapse:collapse; table-layout:fixed; width:310px;}
table td {border:solid 1px #fab; width:100px; word-wrap:break-word;}
<table>
<tr>
<td>1</td>
<td>Lorem Ipsum</td>
<td>Lorem Ipsum is simply dummy text of the printing and typesetting industry. </td>
</tr>
<tr>
<td>2</td>
<td>LoremIpsumhasbeentheindustry'sstandarddummytexteversincethe1500s,whenanunknown</td>
<td>Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.</td>
</tr>
<tr>
<td>3</td>
<td></td>
<td>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna...</td>
</tr>
</table>
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