We won't save the text for the time, but it would be straightforward to do so.
In Wicket, to create page, you have to create the appropriate html page, with some wicket:id attributes in the "Wicket enabled components", and then map it with the Java page.
Considering the textarea, there is a "new Property Model". And, surprisingly, you can spot a "private String textarea" in the page class.
To test your newly created page, just press "Run" in eclipse.
Be aware, however, that some mecanism exists to redirect the user to some peculiar page and then back to the previous one.
It's commonly and easily used to deal with user login and may be part, one day, of another article.
Only some basic knowledge of Java and html are needed.
When you click on the save button, the Eclipse output will appear as expected. If you change something in the html page, it'll be automaticaly picked up by Jetty, as you're in development mode (it's written in the file).
For the change on the Java side, you'll have to restart your application.
It should pick up the file, which contains the main class. Then go on " and you should see something like that : We agree that the look of this page is pretty basic.
But it's just some simple html file : you're free to do whatever you want in it, just go for it.