Untested, should work fine. Not really sure if the defined() test is really necessary, but I figured I'd slip it in.

#!perl -w

use strict;

my %person = map {
    m!^(.*)$!;
    defined($1) and length($1) ? ($1 => 1) : ()
} <DATA>;

__DATA__
Ruth
Samuel
Paul
John
Silas
[download]

quick update: a simple loop would also work of course:

#!perl -w

use strict;

my %person;

while ( chomp($_ = <DATA>) ) {
    $person{$_} = 1;
}

__DATA__
Ruth
Samuel
Paul
John
Silas
[download]