After reviewing a paper in a journal, one after one review invitation keeps coming from that journal every weekend. Does a man have no job but to review papers?
No, receiving multiple review invitations from a journal does not necessarily mean that a person has no job but to review papers. It is common for journals to send out review requests to multiple potential reviewers, and these requests may be sent out at regular intervals until enough reviewers have accepted the invitation. While it may be frustrating to receive multiple invitations from the same journal, it is important to remember that the peer review process is an essential part of the academic publishing process and relies on the voluntary participation of reviewers.
I would suggest you only review the papers that are really interesting to you and fit well with your expertise. These are the principles so I find I usually only review 2 papers per year for a journal. I think that too much more than that is unfair (for reviewers) because all of this work is unpaid.