The important position of tables in HTML is equivalent to the concrete frame in the construction industry. Before div became popular, tables were the world. The main role of the table in the page is page layout and positioning. Only by integrating table planning can a reasonable page layout be designed.
Of course, the more important role of the table is to display data, which cannot be replaced by other codes.
In order to make it easier to see the situation, the effect after setting the table border: