I'm wondering if there are any settings for displaying Representation Name in Table of Contents?
If I use simple symbology I can change the title (by double click on the title in the Table of Contents) or I can delete the text completely. But it seems that Representations don't have this option and the text "Representation: [name of representation]" will be always displayed.
Is there any Display Option Setting for Representations?
Indeed, you can't change representation name directly in Table of Contents or disable it. You give a name to representation when you create it. This name can be changed in Feature Class Properties -> Representations tab (in Catalog window -> right click -> properties).
When you create a legend, however, "Representation: representation_name" can be turned off. Just untick Show Heading and tick Show Layer Name, which is editable in ToC.