It took another hour to empty it completely, throw away the useless items and sort the remainder in piles according to whether or not he would need them from now on. His school and Quidditch robes, cauldron, parchment, quills and most of his textbooks were piled in a corner, to be left behind. He wondered what his aunt and uncle would do with them; burn them in the dead of night, probably, as if they were the evidence of some dreadful crime. His Muggle clothing, Invisibility Cloak, potion-making kit, certain books, the photograph album Hagrid had once given him, a stack of letters and his wand had been repacked into an old rucksack. In a front pocket were the Marauder's Map and the locket with the note signed "R.A.B" inside it. The locket was accorded this place of honour not because it was valuable - in all usual senses it was worthless - but because of what it had cost to attain it.
This left a sizeable stack of newspapers sitting on the desk beside his snowy owl, Hedwig: one for each of the days Harry had spent at Privet Drive this summer.
Harry Potter and the Deathly Hallows
I don't understand the usage of 'this' in this context. What does it refer to?