This works for me!

create table tt ( c1 number, c2 varchar2(10));

contents of the data file (TAB delimited)
raghu.txt
1 first
2 second
3 third
4 fourth
5 fifth


control file
raghu.ctl
LOAD DATA
INFILE 'c:\tmp\raghu.txt'
APPEND
INTO TABLE tt
FIELDS TERMINATED BY WHITESPACE
( c1,c2)

load data:

C:\tmp>sqlldr80 amar/amar@demo raghu

SQL*Loader: Release 8.0.5.0.0 - Production on Tue Aug 28 10:06:41 2001

(c) Copyright 1999 Oracle Corporation. All rights reserved.

Commit point reached - logical record count 5

C:\tmp>

SQL> select * from tt:
C1 C2
-------- --------------
1 first
2 second
3 third
4 fourth
5 fifth


-amar