Briefly explain four challenges often associated with table-based Web page layout.

What will be an ideal response?

1.   Tabular layouts violate the purpose of HTML. A basic philosophy of Web page design is that HTML code should indicate the structure of a document, but not how the document should be rendered by browsers. Tables take control of layout from style sheets, putting page design back into the HTML file.
2.   Table layouts are difficult to revise. Imagine a complex table layout consisting of two columns with several levels of additional tables nested within each column. Now imagine having to revise that table structure, changing it into a three-column layout. This would not be an easy task because the page content would be intertwined with the page layout.
Further, imagine the difficulty of having to repeat that design change for dozens of pages across a large Web site. By contrast, a layout created with a properly designed style sheet is much easier to maintain and revise because it is separate from the page content.
3.   Tables take longer to render. Unless the size of every element in a table is specified, browsers need to first load the table content and then run algorithms to determine how to size each element of the table. This can be time-consuming for large, complex tables that involve many cells and nested elements.
4.   Table layouts are code-heavy. Creating a visually striking table layout often requires
several levels of nested table cells, rows, and columns. The ratio of HTML code to actual page content thus becomes more heavily weighted toward the HTML code, resulting in a document that takes longer to load and that can be difficult to interpret by people who need to edit the underlying code.
5.   Tables can be inaccessible to users with disabilities. Aural or Braille browsers recite the Web page content line-by-line down through the file, but tables convey information both horizontally and vertically. The result is that information that is easily understood visually is unintelligible aurally. On the other hand, with style sheets an aural style could be designed that would better convey such information aurally.