@daniel_sahalI've attached the wrong snip/ Actually it is FULL GC Ergonomics, which was bothering me. Now I am attaching the correct snip.  But as you said I scaled a bit. The thing I forgot to mention is that the table is wide - more than 300 columns. I am not creating extra objects inside the loop except of the dataframe on each iteration, but it gets overwritten on the next one.
I still can't figure out how is the memory building so much in the driver node. Could you give me  some more details about it? For my own knowledge