This old, old page (from about 2001!) related to website pages created using a
<TABLE> for the layout. That layout was quite common at the time, before CSS was truly workable across browsers. This page contained instructions for how to place the text content in the code of the table, before the navigation menu, but still have the navigation menu display to the left side of the page. At that time, it was a common SEO belief that placing the meat of the page before all the navigation code, gave one an advantage in several of the existing search engines of the day. It's a silly thing to do today.
While this code WILL STILL WORK to display the left-hand nav menu before the text of a page (even though it comes AFTER it in the code of the page, it is utterly unimportant to Google or Bing or any other search engine in terms of ranking.
<td><!-- leave this TD empty - it will disappear --></td>
<td rowspan=2>Put the text for the page here. </td>
<td>Put the Navigation Bar Here</td>
That rowspan=2 inside the TD (table data) is what does it. This table displays with the navigation bar on the left and the text of the page on the right. That allows you to get the text for your page closer to the top of the page, so that it is within the first 3kb of the page.
Why was this important? The closer to the beginning of the file, the more important the text in it seemed to be to Google circa the year 2001.
To see this table trick still at work now, visit the Dark Horse Ranch website and click VIEW | SOURCE for the page. The layout of that site (which we built way back in the day) hasn't been updated for more than twenty years.
We haven't used the table trick since about 2002, because we don't use tables when layout out website content (quite aside from the fact it was a fad SEO technique). We recommend using simple, clean and descriptive code, placing all styles in an external CSS style sheet. For that we typically use the Bootstrap platform.