use warnings;
use strict;
use Data::Dumper;

my %hoh;

while (<DATA>)
  {
  my @items = split ' ';
  push @{$hoh{'this'}->{'that'}->{'theOther'} }, [@items];
  }
  
print Dumper (\%hoh);

__DATA__
eggs bacon cheese
tomatoes potatoes onions
beans peas cabbage