I don't see how Text::CSV is not a good answer for this question, both the sample data and the actual scenario described above (nothing in the scenario required regular expressions). Example (error handling left as an exercise):

use strict;
use warnings;
use Text::CSV;
my $ham = "spam\tspam\tspam\t\tyam\tclam";
my $csv = Text::CSV->new({sep_char => "\t", quote_char => undef});
my $status = $csv->parse($ham);
my @jam = $csv->fields();
print join("\n", '**', @jam, '**', '');
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