What is the "#" hidden character in InDesign? How to fix blank pages?

I successfully (sort of) used the InDesign Place function with a Word.docx for text and endnotes. But, it added 1,330 blank pages between the last page of text (p. 100) and the endotes. With the Type/Hidden Characters Shown, each page (except the endnote page) has a blue, hidden "#" mark showing  on the top left. What did I do? I also see on the first page of the text along with the # mark, there is a blue line along the top of the page horizontally, just under the page margin line. Also, on p. 101 after the last page of text, is the another hidden character, one with with a dot and and down button indicator.  Other than these hidden characters, the pages are blank. These are in the screen shots attached. This is the beginning of the 1,330 blank pages. So, I can manually delete the blank pages and be on my way, but if anyone can tell me what exactly I did here, I would like to avoid future problems. After this, I'm typing right into InCopy or InDesign. No more Word for me, even converted from Apple Pages.