I have tried your suggestion and it did help to avoid comments but not for blank lines. Here I am provide the code and config file. Also providing output.

use strict;
use warnings;
use Data::Dumper;
use Text::CSV_XS;
use IO::File;

my $hash_ref = csv_file_hashref('parameters.conf');

foreach my $key (sort keys %{$hash_ref}){
   print qq{$key:};
   print join q{,}, @{$hash_ref->{$key}};
   print qq{\n};
}

sub csv_file_hashref {
   my ($filename) = @_;

   my $csv_fh = IO::File->new($filename, 'r');
   my $csv = Text::CSV_XS->new ();

   my %output_hash;
   while(my $colref = $csv->getline ($csv_fh))
   {
      if ($colref->[0] =~ /^#/) {
        next;
        }
   my $anynonblank=0; 
    for my $item (@$colref){ 
        unless  ($item =~ /^\s+$/) { $anynonblank=1; last; } 
    } 
    unless ($anynonblank) { next; }  
      #print @$colref;
      #print "\n";
      $output_hash{shift @{$colref}} = $colref;
   }

   return \%output_hash;
}
1;
[download]

#sdadwlasda
abc xyz,10

#ldfgld

xyz pqr,2

#jwej

pqr stq,0.1

#
#

#
#
[download]

:
abc xyz:10
pqr stq:0.1
xyz pqr:2
[download]