After installing the plugin, if you create a table to be posted you should get a new pop-up. Choose the tables' width, the amount of columns and rows it's to have, and the cell padding, then 'Create Table'.
You can then select individual cells, and edit it's styling and contents by clicking 'Cell Options', the contents can have HTML formatting. The options pop-up can be dragged to a more suitable position, where it should remain until you choose to change it.
When finished, 'Submit' it to add the code to your post.
If you are the main Administrator of the forum you also have an 'HTML' option, that will give you the HTML coding of the finished table which you can copy/paste to add to your templates or headers/footers.