That's what I would have suggested, with one change: use a hash slice.

# instead of this
my $c = 0;
my @columns = split(/\t/,$_);
push @a, { map { $header[$c++] => $_ } @columns };

# do this
my %row;
@row{@header} = split(/\t/,$_);
push @a, \%row;
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They're functionally equivalent, I know... but it's just that since what you are doing is really a hash-slice, why not use hash-slice syntax?