Maybe this particular file can be split on TAB correctly, but even then, it is not CSV. (The C stands for Comma). There are however several CSV modules that can perfectly deal with TCV data. You might want to try either of these.

using DBD::CSV (utf8 encoded tab-separated .txt files):

use DBI

my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_ext        => ".txt/r",
    f_encoding   => "utf-8",
    csv_sep_char => "\t",
    # more options available
    RaiseError   => 1,
    });
my $sth = $dbh->prepare ("select * from test");
$sth->execute;
while (my @row = $sth->fetrow_array) {
    # do something with the fields
    }
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Using Text::CSV_XS:

use Text::CSV_XS;

my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, sep_char =
+> "\t" });
open my $fh, "<:encoding(utf-8)", "test.txt" or die "test.txt: $!";
while (my $row = $csv->getline ($fh)) {
    # do something with @$row
    }
close $fh;
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