Use Text::ParseWords.

#!/usr/bin/perl

use Text::ParseWords;
use Data::Dumper;

my @data;

while (<DATA>) {
  chomp;

  s/^\s+//;
  s/[\s:,]+\s*$//;

  push @data, [parse_line '[\s:,]+', 0, $_];
}

print Dumper \@data;

__DATA__
  COLUMN_A: "Y","N"
  COLUMN_B:
  COLUMN_C: "something", "something else", "and more"
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