My Sony Vaio Z from 2009 or 2010 looks at your Dell in contempt: 13.1" FullHD screen at 314mm x 210mm (we'll pretend the thickness does not matter ;)) and 1.36kg. Vaio TT was even smaller footprint.

But even in 2018, you could get an X1 Carbon at 1.13kg and 323mm x 217mm x 15.5mm.