How about one on these http://www.amazon.co.uk/Acer-11-6-inch-Netbook-Integrated-Graphics/dp/B008MKNSYK/ref=sr. Although it is called a netbook, in reality it is a mini-laptop with an 11" screen. It has a dual core processor, 4Gb of RAM, a 500Gb hard drive and Windows 7 home premium operating system. I bought one of these for the same reason you have, to be light and easily portable when travelling.
Sony Xperia Z5 review: Hands-on with the phone which the Z3+ should have been