The HTML 3.2 DTD defines a stripped down version of this rfc, which closely matches Netscape's implementation of tables in May 1996. Here is a short description of how tables work from rfc1942 of May 1996.
Tables start with an optional caption followed by one or more rows.
Each row is formed by one or more cells, which are differentiated into header and data cells. Cells can be merged across rows and columns, and include attributes assisting rendering to speech and braille, or for exporting table data into databases. The model provides limited support for control over appearence, for example horizontal and vertical alignment of cell contents, border styles and cell margins. You can further affect this by grouping rows and columns together. Tables can contain a wide range of content, such as headers, lists, paragraphs, forms, figures, preformatted text and even nested tables.