Looks like it should work to me. You could test it with something like the following:

my $hashref = {};
my @params = qw( abc_1 abc_2 abc_3 cba cdr car );

foreach my $param (@params) {
    if ($param =~ /^abc_/) {
        $hashref->{$param} = [ 'column', 'text' ];
    }
}

use Data::Dumper;
print Dumper($hashref);
[download]

Assuming you trust your ability to get reliable data from CGI::param() (and there's no reason not to), you should be safe.

I can't see any reason why this wouldn't work right. However, I'd probably skip the if check and build a hash of allowed parameters and array references and do something like:

foreach my $param ($cgi->param()) {
    if (defined(my $arr_ref = $options{$param})) {
        $hashref->{$param} = $arr_ref;
    }
}
[download]

It depends on what you're doing with $hashref, I suppose.