this book is an "Ortsfamilienbuch" OFB on the community of Emden near Magdeburg and not Emden in Lower Saxony. It will comprise mostly Christian families. Very often these sorts of books don't even give a hint on a Jewish community. Here is a link to the family names supposedly mentioned in the book:
Especially for Jewish Families of Emden and the region Ostfriesland, I would like to recommend the following book:
Die jüdischen Famiien in Leer und ihre Herkunft Band 1 / Band 2
Upstalsboom-Gesellschaft für historische Personenforschung und Bevölkerungsgeschichte in Ostfriesland e.V.
Even though it is explicitly about Leer, many families of Emden are included, too. It includes photographs of tombstones and information on sources to information about the people living there.
Regards from Germany,