I am also looking for this kind of functionality! I would to save multiple items to a collection at once; for instance, when I am browsing a bundle I find a number of items I would like to add to one or another of my collections and instead of pulling up each game page individually and saving them one by one to a collection I would like to be able to select, say, 2 or 3 of them and add them all to a specific collection. As someone who can only use a mouse and keyboard for so long before my wrists and hands hurt too much for me to continue, this would greatly help me when I find a bundle that contains a number of games I would like to save for future perusal!