Hello There,
Most of the time, when you copy and paste from MS Word, there are styling that comes with it. It is best that you copy it from Word and paste it in a text editor like Notepad and then from Notepad, you copy it again before pasting it to the WordPress Visual Editor. This is the safest way of copying and pasting of a document content especially from MS Word.
Would you mind to point us to the url of the page in question? Thanks.