Seemingly-irrelevant papers, all with author in common, suggested by reviewer
Think of the review process as a debate between you and the reviewers, with the editor as jury. You would like to convince the reviewers, but ultimately, you want to convince the editor. The editor has called in the reviewers as domain experts so will listen to what they have to say. But ultimately the editor makes up their own mind. It's just that the editor is most likely to give their go-ahead if you and the reviewers come to an agreement. But it's possible that the editor decides to publish even if a reviewer is not positive.

Also, consider that editors are basically the experts on the subject of "reviewers". 

I would write three responses. The responses addressed to the reviewers are also passed through the editor (after all, the reviewers are anonymous).


One to the first reviewer, thanking them for their good advice and noting how you'll apply that. This helps to show to the editor that you're taking the review process seriously.
A second one to the second reviewer where you explain why you don't think those seven papers are relevant to your paper. Don't put any accusations here, just give your considered, good-faith view on the relevance of those seven papers.
A third note to the editor only, where you express concern that the second reviewer's review was rather short, that you don't really see the relevance of the papers, and that you noticed that they all have a common author. Ask for the editor's advice on how to proceed.


At that point the editor will probably take a second look at the rather poor quality review, and compare the author list of the proposed seven citations to the name of the reviewer. And advise you on how to proceed.