use strict;
use warnings;

use Data::Dumper;

open my $inFH, q{<}, \ <<END_OF_FILE or die qq{open: $!\n};
START DATA
1 2 3 4 5 6 7
a bb ccc ddd
9 8 7 6 5
END DATA
START DATA
4.9 5.3 9.1
biff baff boff
END DATA
END_OF_FILE

my @block = ();
local $/ = qq{END DATA\n};

while ( <$inFH> )
{
    my @lines = split m{\n};
    push @block, [ @lines[ 1 .. $#lines - 1 ] ];
}

close $inFH or die qq{close: $!\n};

print Data::Dumper->Dumpxs( [ \ @block ], [ q{*block} ] );