I somehow found a solution it's very awful

, but at least it did solve my problem.
in lazreport I made a single master data band and I counted how many rows needed to fill all the page which was in my case 59 .
I made a temp table as an Adapter, I fill on it all my mater data/ detail fields successively
using two loops blocks . inside the master loop block, I made a check if (line mod 59 = 0) then insert an empty line which will eventually push this last line to a new page and VOILA, thank you GAN I hope you see this reply