title: Create merged tables in R
body: <p>I have some data in multiple large data tables in R. I wish to merge and produce counts of various variables.</p>
  
  <p>I can produce the counts within individual tables easily using the 'table' command, but I have not yet figured out the economical (preferably base R, one liner) command to then produce combined counts.</p>
  
  <pre><code>aaa&lt;-table(MyData1$MyVar)
  bbb&lt;-table(MyData2$MyVar)
  
  &gt; aaa
  Dogs     3
  Cats     4
  Horses   1
  Sheep    2
  Giraffes 3
  
  &gt; bbb
  Dogs     27
  Cats      1
  Sheep     2
  Ocelots   1
  </code></pre>
  
  <p>Desired Output:</p>
  
  <pre><code>Dogs     30
  Cats      5
  Horses    1
  Sheep     4
  Giraffes  3
  Ocelots   1
  </code></pre>
  
  <p>I am sure there is a straightforward Base R way to do this I am just not seeing it.</p>