A hidden table is not normally visible as such. Normally, the background color is the same as the rest of the page, and there are no grid lines to indicate that the table is present. Its only effect is to arrange and align the contents of the table cells into a regular grid. This can result in a more pleasing layout than the default HTML standard.

Hidden tables can be used to create a number of effects. They can, for example, hold a number of images in a fixed spatial relationship to each other. Decorative borders can be created by assembling small component images like tiles. Multi-column text is another possible effect, as shown here. You'll probably want to use a small amount of padding around each cell so that the text in one column doesn't run up against the text in the neighboring column.

One of the disadvantages of hidden tables is that they are very exacting, and a single mistake may ruin the intended effect. In particular, different browsers often have different ways of displaying the same elements. This can throw off your table formatting in unpredictable ways. For example, different window sizes may cause one column to be formatted longer or shorter than the rest.

Finally, using tables for formatting undermines the style/content separation to a certain extent. This may be a necessary evil, but should be kept in mind. If you format your pages using hidden tables, and later decide to change the formatting style, you will probably have to edit every page in your site individually.