Let's begin with the benefits of a tableless layout. These are only in the order that I feel they should go in, some things are more important to other people, so rank them as you will.

Forces You To Write Well-Formed Code

You cannot have a properly made tableless layout, and use improper and non-standard code. Well, let me correct that - you can (technically you can do it) but it defeats the whole purpose. When you are creating a tableless design, you should be using standards compliant code. I think that anything that makes you get into the habit of always writing clean code is a good thing.

Faster Loading Time

This is absolutely a benefit of a tableless layout, and for several reasons. First, on a fundamental level - tables load slowly. For the most part, unless you set the height and width of your table elements, all the text has to be loaded and rendered BEFORE the table sizes itself to the page. Of course, this is what so many people loved about tables isn't it? The fact that they were so easily sizeable. The downside is how much more time they take to load. Okay, so the solution to that loading time is to set all the values explicitly, right? So now we see another downside. Code clutter that increases loading time. First of all, just by themselves, tables take allot of code. How many td open and close tags does your average table based layout have? Tons. Having to set all the values explicitly only adds to the page size and loading time.

Easier to Read Code

If you are using standard code, semantic document conventions, and a tableless layout, your code can be so clean that it looks practically like just regular text with a few extra symbols. That is a great benefit because it not only makes it easier for you to update, but it makes it easier for a non-technical user to make small alterations to. Additionally, if you work as a web developer in a more freelance capacity, it is common for there to be a full-time web developer who has to maintain that site. Clean and simple to read code makes that an easy transition. We like it when people leave us easy to understand code, right? Let's return the favor.

Print Alternate Views

When you create a page using a table-layout, you are rather unfortunately locked into a certain layout. Developers who have created table-based websites, as most of us have at some point - particularly if you were in the the industry before the big tableless movement, know that you often have to create a separate printable version of your pages. This can be, needless to say, quite tiresome. Ease of printing style control is a huge benefit with a tableless layout. You can easily create a single new printing style that applies to all your pages, instead of making them individually. That alone is a huge time saver, but there is more. While you can control all elements with this approach, the biggest key is organization of information within the page itself. Using the example, let's assume that the display order we want all our pages to print using the following order: The page header first, the content next, the special news after that, then the link list, and then the footer. However! We still want it to display as it would normally when viewing (meaning the header at the top, the links on the left, content in the middle, news on the right, and footer at the bottom). With a table-based layout, you would have to create a new page to do that special printing organization because the print style will read your columns left to right. With a table-less layout, you are not bound by this. You can order the content in your page however you like, and still control the way it looks... all by using the CSS only! Additionally, because we can put the content in whatever order we want in the HTML, and then move the content blocks around for website viewing using CSS - we can have ultimate control over presentation.