Performance impact of using the universal selector in CSS
The problem with the universal selector is that... it's universal. It's affecting all descendants, present and future. Impact is not really noticeable in small scale, but when your app starts to grow (like packing more and more stuff in &lt;td&gt;), or if fast rendering is critical (like say render at 60fps for smooth animation), then the effects will show.

The way you're asking this question seems to imply that you're using tables for layout. Otherwise, &lt;td&gt; content shouldn't be that many to warrant a universal selector. Don't use tables for layouting. Tables don't get rendered until all the markup of the table (from &lt;table&gt; to &lt;/table&gt;) is parsed. In the meantime, all you will be seeing is a big blank space. Not good.