Select...Into Table

DATA: itab LIKE SPFLI OCCURS 0 WITH HEADER LINE.
SELECT * FORM SPFLI INTO TABLE itab.

Select...Append

DATA: itab LIKE SPFLI OCCURS 0 WITH HEADER LINE.
SELECT * FORM SPFLI INTO itab.
  APPEND itab.
ENDSELECT.

In above logic, Select...Into Table is faster than Select...Append.