CSS Grids vs Table Grids
Table Grids were the original scheme to control the placement of images and text in different parts of the page. We place images and text in different cells of the table to acheive control over placement. However, tables allow very limited formating differences. All the cells have the same properties- width, borders, colors,etc.
CSS divs provide a more flexible solution. We are able to create boxes of various widths, heights, borders, etc and place them anywhere on the page independently of other boxes. Furhter, in responsive web design, these boxes can be given different sets of properties as required by the screen size of the user's device. This is not possible with table grids.