title: Merge two tables in R
body: <p>I have two tables, which have the same column names, number of rows and columns:</p>
  
  <pre><code>ID     Q1        Q2
  1      aa        bb
  2      cc        12
  3      q         z
  
  
  ID     Q1        Q2
  1      A         B
  2      p         l_
  3      23        r
  </code></pre>
  
  <p>I would like to have in the next table merged those above columns with both context and separated by \n, like this: </p>
  
  <pre><code>  ID     Q1        Q2
    1      aa        bb
           A         B
    2      cc        12
           p         l_
    3      q         z
           23        r
  </code></pre>
  
  <p>I have tried, <code>merge</code>, <code>rbind</code>, <code>cbind</code>, but I didn't get any good results. 
  Any ides how to do this? </p>
  
  <p>Required result:<br>
  <a href="https://i.stack.imgur.com/TrGxw.png" rel="nofollow noreferrer">enter image description here</a></p>