var conversion = require("html-to-xlsx")();
conversion("<table><tr><td>cell value</td></tr></table>" }, function(err, stream){
  //readable stream to xlsx file
  stream.pipe(res);
});

var conversion = require("html-to-xlsx")({
  /* use rather dedicated process for every phantom printing,
	  "dedicated-process" strategy is quite slower but can solve some bugs
	  with corporate proxy, default is "phantom-server" */
  strategy: 'phantom-server', // 'dedicated-process' or 'phantom-server'
  /* number of allocated phantomjs processes */
	numberOfWorkers: 2,
	/* timeout in ms for html conversion, when the timeout is reached, the phantom process is recycled */
	timeout: 5000,
	/* directory where are stored temporary html and pdf files, use something like npm package reaper to clean this up */
	tmpDir: "os/tmpdir",
	/* optional port range where to start phantomjs server */
  portLeftBoundary: 1000,
  portRightBoundary: 2000,
  /* optional hostname where to start phantomjs server */
  host: '127.0.0.1'
});

// kill all phantomjs workers when using phantom-server strategy
conversion.kill();