The "Insert Objects" (also known as "Paste HTML Code") icon allows you to insert html and scripts in the page editor. With the "Objects" button, you can insert a specific piece of HTML into the page in a specific position on the page while using the WYSIWYG page editor. This can be somewhat less confusing for some as you do not have to look through the source code to find the appropriate place to put the code and you do not have to use html to set the location. This is especially helpful with scripts.
For more information about HTML and Scripts, please visit the "HTML and Scripts" (link) help pages.