I'd use Scalar::Util::looks_like_number in addition: 
#!/usr/bin/perl

use warnings;
use strict;
use Data::Dumper;
use Scalar::Util qw(looks_like_number);

my $data = [];
while (<DATA>) {
    chomp;
    if (/^(\w{1,2})$/) {
        push(@$data, [$1]);
    } elsif (looks_like_number($_)) {
        push(@{$$data[-1]}, $_);
    }
}
print Dumper($data);

__DATA__
C
 -2.3242E-003
 1.32423
 0.34243E+002
 -3.23134
MD
 0.34243E+002
 -3.23134

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In reply to Re^2: Read fortran list output by pjotrik
in thread Read fortran list output by madd

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