title: Convert list of lists to delimited string
body: <p>How do I do the following using built-in modules only?</p>
  
  <p>I have a list of lists like this:  </p>
  
  <pre><code>[['dog', 1], ['cat', 2, 'a'], ['rat', 3, 4], ['bat', 5]]
  </code></pre>
  
  <p>And from it, I'd like to produce a string representation of a table like this where the columns are delimited by tabs and the rows by newlines.  </p>
  
  <pre><code>dog 1
  cat 2   a
  rat 3   4
  bat 5
  </code></pre>
  
  <p>i.e.  </p>
  
  <pre><code>'dog\t1\ncat\t2\ta\nrat\t3\t4\nbat\t5'
  </code></pre>