Hi Oskar,
PSA table was generated while activating the data source at BW Side not replication time.
Replication mean its just transferring ecc data source structure(its psa structure) to bw side. Once we replicated data source into bw server, then we can do activate. While doing activation of data source at back-end PSA table will generate.
Actually we get some errors like there is no PSA table, at that time we can active the data source automatically psa table regenerate.
While activating the data source you can observe messages which are generating at below status bar, you may find PSA table name also.
Thanks