Just wondering why you choose to edit the Word Document in Word. It would be easier probably to edit the data in a string or table within UiPath, then when your data is updated, output to your document.
If you do want to use the menu options in Word, let me recommend you to use the Alt+keycombinations. If you press the Alt key you will notice characters over the menu items and if you press one, another set of characters are displayed within that menu item.
However, like I said, it might be more reliable and easier to use String or Table manipulation to create your data that you want to output, then write it to the file.