Up to now, tables did not work very well on our new site because they were not responsive, eg, they looked AWFUL on a mobile device. Now, you can now insert tables and they will resize beautifully on smaller screens. Tables must be used for data only, not to design or lay out your page.
For example, here is the table at full width:
And the same table displayed on a mobile device:
To insert a table, use the new buttons in the editor. You should (probably) set the first row to be a header: