You can't merge the image data in access directly into Word. The best you
can do is maintain copies of the images in files outside the database in a
format that Word can insert using an INCLUDEPICTURE field, and keep enough
information in the record that the image comes from to build the file name
of the image. For example, if each record has a unique numeric key called ID
wwith values 1,2,3, etc., then you might save each image as

c:\myimages\img1.jpg
c:\myimages\img2.jpg
c:\myimages\img3.jpg

etc., then use the following nested field in Word:

{ INCLUDEPICTURE "c:\\myimages\\img{ MERGEFIELD ID }.jpg" \d }

All the {} have to be the special field code braces you can insert using
ctrl-F9.

Then you may also have to output your merge to a new document, select it
all, and press F9 to update the fields.