A family of Microsoft word processing software products for creating web, email, and print documents.
To add to what Charles has said, the document and table set up by the Labels dialog play some tricks that aren't available when you create a document and table without the dialog. For one thing, it overrides the minimum margin settings that come from the printer driver and it ignores the usual header and footer heights.
If the physical labels you're printing on aren't listed in the Product Number box or come from a vendor that isn't listed, you can click the New Label button in the Label Options dialog and enter the measurements manually; they'll be saved as a Custom label (the "Other/Custom" entry will be added to the Vendor list). It will probably take some trial and error to get the measurements exactly right, so try printing a sample on plain paper and holding it and a sheet of labels up to a strong light to check the positioning.