So ...

Upon activation, you need to go to Templates => Add New to create your first template.

Now, a template is basically a custom post type with a usual, fully functional Wordpress editor.

It means that you can use both the visual and the text editor to create your new custom content template. You can use any element supported by your editor, you can add images or other media files, etc.

So give it a name and start creating the content block that you want to reuse in your posts or pages.

I am going to create a new table template:

And that's it ... When you are happy with your newly defined content template, simply hit the "Publish" button.

OK. Now let's see the magic ...