I cannot give a complete, definitive answer because I am usually too busy diring corpse runs to study the mechanic. I will attempt to make a point or two.

The best case is to make a naked corpse tun in which the newly re-spawned viking has nothing in his or her personal inventory. In such a case, everything will be collected by clicking on "Take All." Items which were in the hot bar of the viking at the time of death will be slotted in the hot bar of the re-spawned viking in the same slots in which they were originally located. Items in the lower three rows of the corpse inventory will all be picked up but not necessarily in the same slots.

At times, a re-spawned viking simply must take a shield and a weapon and perhaps other items, to have a hope of making it to the corpse alive. If those items are placed in the re-spawned hot bar, the items in the corpse's hot bar at the time of death will not be placed in the re-spawned viking's hot bar. Corpse hot bar items which cannot be placed in the re-spawned hot bar may or may not be picked up depending, I think, on whether there is room in the lower three rows to hold all the remaining corpse items.

In regard to corpse items not in the corpse's hot bar, I simply have no idea of the priority the "Take All" mechanic gives them. It also seems to me that a half stack of say stone in the corpse inventory will not always be combined in one slot with a half stack of stone in the re-spawned inventory.

I hope to pay more attention on future expeditions to retrieve items from corpses.