This is a Google App Script that "downloads" many attachment at once to Google Drive. Label the mails to download with "GmailDownload" and run the script.

bunch_downloader.gs

function onOpen() {
  // Setup the drive folder
  var date = new Date();
  var fold = DriveApp.createFolder("GmailDownload-" + date.toISOString());
  
  var log = "";
  
  // Get the label with gmail threads
  var label = GmailApp.getUserLabelByName("DriveDownload");
  
  //Logger.log(label.getUnreadCount());
  var threads = label.getThreads();//0, 5); // for DEBUG only 
  for (var i = 0; i < threads.length; i++) {
    log += "\nProcessing thread" + threads[i].getFirstMessageSubject() + "\n";
    var msgs = threads[i].getMessages();
    for (var j = 0; j < msgs.length; j++) {
      // Get array of attachments
      var atc = msgs[j].getAttachments();
      if (atc.length == 0) {
        var errorMessage = "WARNING! No attachment in message " + j + " for mail " + msgs[j].getSubject() + " from " + msgs[j].getFrom();
        log += "  " + errorMessage + "\n";
        Logger.log(errorMessage);
        continue;
      }

      // Create a folder for each message
      var fname = msgs[j].getFrom() + " - " + msgs[j].getSubject();
      var msgFold = fold.createFolder(fname);
      // Download the files
      for (var k = 0; k < atc.length; k++) {
        var file = msgFold.createFile(atc[k].copyBlob());
        file.setName(atc[k].getName());
      }
    }
  }
  
  var logFile = fold.createFile("log.txt", "GMail Bunch Downloader - Logfile\n\n" + log);
  
  // Remove the label
  label.deleteLabel();
}