local $/ = \500;

##</code><code>##

#!/usr/bin/perl -w
use strict;
use warnings;
local $/ = \500;
open IN, '<', 'bigfile.csv' or die $!;

my @values;
while (my $line = <IN>) {
    push @values, split /,/, $line;
    while (@values > 10) {
        print join(',',@values[0..9]), "\n";
        @values = @values[10..@values-10];
    }
}
close IN or die $!;