Hi @JamesFinlayson,
Welcome to the Instructure Community! We're glad you found the site, even if it's not under the best circumstances.
Whet you're experiencing is likely that there are some core differences between print formats (like Microsoft Word) and web format. One of the biggest fundamental differences between the two is that print format has a specific page/paper size (letter, legal, A4, etc) and web content is usually dynamically sized based on the device and browser window the user has. This may not seem too important to the conversation right now, but I'd say i's one on the reasons web formatting diverges from print.
When you copy/paste from Word, the Canvas rich content editor (RCE for short, the textbox you type or paste everything into) does some conversions of the behind the scenes code to help translate the print format over to the web format in the best way it can without making things over-complex and keeping with the Canvas standards. The things you're most likely to notice differences in right away would be line spacing, image size/placement, and tables just in general.
Without seeing exactly what things look like on your end, I'm guessing your bold/underlined things are generally coming over as intended, but the tables are likely the source of your frustration. Am I correct? If so, could you maybe provide some screenshots of the content in both Word and Canvas so we could see the differences?
I hate to say this, but it's going to be very hard (if not impossible) for content to be copy/pasted from Word to any web platform and have it look identical. There could perhaps be some improvements so how Canvas handles some things, but it wouldn't be a quick or easy thing to address, and could honestly make things worse overall rather than better.
I wonder if there could be a workflow that would be better for you than working in Word. Could you perhaps share the reasons for your current workflow? Are you teaching multiple classes, some that need printed documents and some that need online content, just want to have a personal backup version of your content, etc?
We look forward to hearing back form you soon. The more info you can give us, the more likely it is that someone will be able to give you some potential workarounds or other guidance.
-Chris