Text modules are familiar from word processing programmes. Text passages that are often repeated can be added with a click. You can proceed in a similar way with formats in TinyMCE. I am interested in the general principle. That is why the example here is again kept simple. A text is simply given a red background.
Cassiopeia offers Bootstrap 5. Get inspired for your own use cases in the Bootstrap Documentation[getbootstrap.com/docs/5.0], if you don't already have a lot of ideas yourself. An often used use case is a table that is created for design purposes only. In HTML, it is a bad idea to use a table for presentation purposes only, because it does not reflect the semantics. Other elements make more semantic sense and look just like a table. In the simplest case, the Grid[^getbootstrap.com/docs/5.0/layout/grid/]
Create a template for use in TinyMCE in Joomla 4.
First we create the file
redBackground.html in the directory
<!-- /templates/cassiopeia/html/tinymce/redBackground.html --> <div class="redbackground"><p>Text</p></div>
You must adapt the paths shown in the following image to your individual environment if you are not using Cassiopeia as the standard template - or a child template.
Now create an article and select the menu item for inserting a template in the TinyMCE menu.
If there are several templates in your installation, you can choose.
Depending on which HTML markup your template contains, it is now inserted. If you have used my simple example, the code
<div class="redbackground"><p>Text</p></div> will be inserted.