Very helpful. I will add that as of 2.1.1 on Windows the 'Data Merge' is under Window>Data Merge, and the Field panel is under Window>References>Fields. Also, you can add images like this the same way, just put the path to the image file in the excel file as another column!
Thank you so much for your tutorial. Very clear and, instructive, easy to follow. I am using Affinity Publisher v2 and needed data to merge for "Certificate" templates. I first came to the official Affinity tutorials, but I found them hard to follow, and I didn't succeed. Despite this tutorial being for v1, my data merge was quickly set up and running. Great work!