There are multiple levels of headers (heading 1 through heading 6) that you can use to organize the article.
Click on the table icon in the toolbar. You'll get a popup that asks you for the number of rows and columns you need (you can add more after you create the table). Enter the information and click OK. You'll get a table:
|Row 1, Column 1||Column 2|
Sometimes you want to add a heading to a table. Place your cursor in the table and right click to get a popup menu. Select "Table Properties" from this menu. On the left, you'll see a drop-down box for headers. Select "First Row", "First Column" or "Both". If you select "First Row", your table will look like this:Row 1, Column 1 Column 2
If you select "First Column", your table will look like this:Row 1, Column 1 Row 2 Row 3
If you select "Both", your table will look like this:Row 1, Column 1 Column 2 Row 2 Row 3