We're reaching the limit of how detailed my help can be. You appear to be using a latter version of Microsoft's Office suite, but I don't even know which version. I can't tell what features and/or procedures Microsoft changed. However I'll look in some of my reference material (written for the older versions of Office) to see if they show any flexibility in things like field selection and mail merge output formatting.
Reports like this is one of the things Access made simple, but many people decided the database capabilities of Excel were adequate and bought the less expensive Office bundles that lack the Access program.
Edited to add:
As far as I can tell the image you posted is a record selection pop-up. Once you uncheck unwanted limes like the headings and blanks at the top you would probably return to the word document by clicking the "OK" button at the lower right. The reference books I have for earlier versions of Office
show a mail merge tool bar near the top of the merged Word document window. The user can move the insertion point to the desired location and select the desired field from the a drop down on the mail merge toolbar. In the merged Word document the field name appears in angle brackets (<<Part Number>>) and should be subject to the usual formatting functions (justification, font, size etc.). The user can then move the insertion point to where the next database field should appear. The toolbar in the earlier versions featured buttons that allowed the user to preview actual data in the document and move from copy to copy (typical first, previous, next and last icons similar to those you would expect in a media player). Of course the buttons are probably prettier in the more recent versions.
I suspect the mail merge acquires field names from the first line of the table. I don't know to what extent the presence of things like a title and blank lines affects that process. The process might
be facilitated if the spreadsheet uses "Header/Footer" on the "Page Setup" pop-up to produce those elements instead of using cells in the spreadsheet itself. Row heights and cell formats like bold face, a different font or borders can be used to visually separate the field headers from the rows containing data.