DECLARE
   TYPE subno_table_type IS TABLE OF trans_deicmain1.subno%TYPE
      INDEX BY BINARY_INTEGER;

   subno_table   subno_table_type;
   k             NUMBER           := 1;
   s             NUMBER           := 1;
BEGIN
   GO_BLOCK ('BLOCK7');
   FIRST_RECORD;

   LOOP
      IF :block7.check1 = 'Y'
      THEN
         subno_table (k) := :block7.subno;
      END IF;******************************
The problem may be here, here you put END LOOP instead of END IF;

      k := k + 1;
      EXIT WHEN :SYSTEM.LAST_RECORD = 'TRUE';
      NEXT_RECORD;
   END LOOP;

   FIRST_RECORD;
   k := 1;
   GO_BLOCK ('BLOCK2');
   FIRST_RECORD;

   LOOP
      IF :block2.subno = subno_table (k)
      THEN
         k := k + 1;

         INSERT INTO block2
              VALUES (:block2.subno, :block2.NAME);
      END IF;

      EXIT WHEN :SYSTEM.LAST_RECORD = 'TRUE';
      NEXT_RECORD;
   END LOOP;
END;