Padding a table row

The trick is to give padding on the td elements, but make an exception for the first (yes, it's hacky, but sometimes you have to play by the browser's rules):

td {
  padding-top:20px;
  padding-bottom:20px;
  padding-right:20px;   
}

td:first-child {
  padding-left:20px;
  padding-right:0;
}

First-child is relatively well supported: https://developer.mozilla.org/en-US/docs/CSS/:first-child

You can use the same reasoning for the horizontal padding by using tr:first-child td.

Alternatively, exclude the first column by using the not operator. Support for this is not as good right now, though.

td:not(:first-child) {
  padding-top:20px;
  padding-bottom:20px;
  padding-right:20px;       
}

Option 1

You could also solve it by adding a transparent border to the row (tr), like this

HTML

<table>
    <tr> 
         <td>1</td>
    </tr>
    <tr> 
         <td>2</td>
    </tr>
</table>

CSS

tr {
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
}

Works like a charm, although if you need regular borders, then this method will sadly not work.

Option 2

Since rows act as a way to group cells, the correct way to do this, would be to use

table {
    border-collapse: inherit;
    border-spacing: 0 10px;
}

In CSS 1 and CSS 2 specifications, padding was available for all elements including <tr>. Yet support of padding for table-row (<tr>) has been removed in CSS 2.1 and CSS 3 specifications. I have never found the reason behind this annoying change which also affect margin property and a few other table elements (header, footer, and columns).

Update: in Feb 2015, this thread on the [email protected] mailing list discussed about adding support of padding and border for table-row. This would apply the standard box model also to table-row and table-column elements. It would permit such examples. The thread seems to suggest that table-row padding support never existed in CSS standards because it would have complicated layout engines. In the 30 September 2014 Editor's Draft of CSS basic box model, padding and border properties exist for all elements including table-row and table-column elements. If it eventually becomes a W3C recommendation, your html+css example may work as intended in browsers at last.