To start adding a table click on the table press tab
To make a new Table hit the add new table button and then you will be brought here:
Enter in the title and description here, as well as the number of columns and rows. You can add additional rows and columns later.
If you scroll down you will see more table options. Start off with only the top three default options checked. The less options you use the better, you do not want a table to become cluttered will options and features you do not need.
After you are done adding the information hit the save button. To use the table you can use the element, or you can use the text editor to add it in.