title: Read xlsx file using data.table::fread(), but selecting the sheet
body: <p>I'm not founding any argument in the <code>fread()</code> function to let me select the sheet I want.<br>
  I'm trying this:</p>
  
  <pre><code>tab &lt;- data.table::fread('myfile.xlsx')
  </code></pre>
  
  <p>As my file has many sheets, how can I select just one of them by sheet name?</p>