title: Can we put hash tables inside a hash table?
body: <p>Can we link another hash table for each key, in a hash table? </p>
  
  <p>My target is to have a very fast 2-d data structure to store cells in a spreadsheet.</p>
  
  <p>I'll store "all columns within a row" in a hash table. Then do this to all 'r' number of rows. Next make the final hash table for rows and store all the 'r' number of hash tables in the new hash table. is this way efficient? or is there a better way?</p>