The function below, when called, will print HTML code containing a link to an encoded version of an RData file.

setDownloadURI = function(list, filename = stop("'filename' must be specified"), textHTML = "Click here to download the data.", fileext = "RData", envir = parent.frame()){
  require(base64enc,quietly = TRUE)
  divname = paste(sample(LETTERS),collapse="")
  tf = tempfile(pattern=filename, fileext = fileext)
  save(list = list, file = tf, envir = envir)
  filenameWithExt = paste(filename,fileext,sep=".")
  
  uri = dataURI(file = tf, mime = "application/octet-stream", encoding = "base64")
  cat("<a style='text-decoration: none' id='",divname,"'></a>
    <script>
    var a = document.createElement('a');
    var div = document.getElementById('",divname,"');
    div.appendChild(a);
    a.setAttribute('href', '",uri,"');
    a.innerHTML = '",textHTML,"' + ' (",filenameWithExt,")';
    if (typeof a.download != 'undefined') {
      a.setAttribute('download', '",filenameWithExt,"');
    }else{
      a.setAttribute('onclick', 'confirm(\"Your browser does not support the download HTML5 attribute. You must rename the file to ",filenameWithExt," after downloading it (or use Chrome/Firefox/Opera). \")');
    }
    </script>",
    sep="")
}

Make sure your results is equal to asis in the block where setDownloadURI is called.

As seen here, a file containing the R objects will be encoded into the HTML file. Large objects, of course, will make for a large HTML file. Note that the file will be base64 encoded, which increases the size of the file by about a third (over the binary RData file).