Did you use warnings and use strict when you ran the code?

But that aside, you are doing some strange things:

my $k=0,$str="";
 for(my $i=0; $i<4;$i+=1)  { 

    @entry=undef;
    for my $j (0..7) { 
        $h{"BUCK_$j"} = $bucket[$k+$j]; 
        push @entry,\%h;
    }
[download]

The loop above will add 8 identical references to %h to @entry.

    $hash_table[$i] = { ENTRY  => [@entry]};
    $k+=8;
 } #end of for i

for(my $i=0; $i<4;$i+=1)  {
    print "ENTRY-0-BUCK-0::", 
        $hash_table[$i]->{ENTRY}->{BUCK_0}, "\n";
[download]

You can't address $hash_table like that since it is an array of hash references containing just the key ENTRY (which is a warning sign) that has the value array reference containing hash references.

}
[download]

Did you try following the advice and tried Data::Dumper on, say, (updated) @hash_table?