You can use a third party utility called rlwrap.
rlwrap is a readline wrapper, a small utility that uses the GNU
readline library to allow the editing of keyboard input for any other
command. It maintains a separate input history for each command, and
can TAB-expand words using all previously seen words and/or a
user-specified file.
So you will be able to use arrows and also get a command history as a bonus.
After you have installed the utility run sqlplus the following way:
$ rlwrap sqlplus