I'm afraid I don't know the correct jargon for what I want to achieve, but I can explain it.

What I want to do is create a restricted document which allows to user to perform the following actions, only:

Save/Save As.
Select one of the following styles: Normal, Title, Heading 1, Heading 2, Heading 3.
Bold.
Underline.
Italic.
Format as list.
Insert table.
Insert image from file.

That is all.

Is this possible? If so, how can I do it?

Thanks in advance.