<tr> is always placed first in the code and means TABLE ROW. <td> is then stated in the table code, and means TABLE DATA. <td> is most frequently manipulated to show images, text and links. Whenever u want data in a new row close the <tr> tag like this </tr> and open a new tag.
The same must be done when you want data in a fresh column. Ie. <td> tag must be closed and a new one opened.

NB. tables are defined in terms of RowxColumn ie. 1x1 etc.
<table><tr><td></td></tr></table>

NB. In this example external links ARE USED but not put inside d <td> tag
<table><tr><td>text</td><td><a href="http://rules-wap.wapka.mobi">Fun Downloads</a></td><td>text</td></tr></table>

<table><tr><td>text</td></tr><tr><td><a href="http://rules-wap.wapka.mobi">Fun Downloads</a></td></tr></tr></td><img src="http://rules-wap.wapka.mobi/logo.gif" alt="*"/></td></tr></table>

text

Fun Downloads