In order to create a table, go to the Resource Browser, select Table from the drop-down in the top-left New category and press the Create button. On the next page (see screenshot to the left you can configure the initial layout of the new table. These settings can be changed later with help of the table control buttons in the toolbar of the Table Editor (add/remove row, add/remove column).
You can declare the first row and/or column as table header cells. This will affect the rendering of these cells - typically they will be rendered with a darker background color, depending on the layout settings.