Error During BULK Insert?

I made two runs for bulk insertion

In first run, 16,36,897 were inserted successfully in around 38 seconds.But in second run, 54,62,952 records had to be inserted, but process failed after 708 seconds with following error :

Error report:
ORA-04030: out of process memory when trying to allocate 980248 bytes (PLS non-lib hp,DARWIN)
ORA-06512: at line 21
04030. 00000 - "out of process memory when trying to allocate %s bytes (%s,%s)"
*Cause: Operating system process private memory has been exhausted
*Action:

Here is my code snippet :
.......
FORALL i in products_tab.first .. products_tab.last
INSERT INTO tab1 VALUES products_tab(i);
COMMIT;
.........

I think that there should not have been any problem in getting it completed successfully.