Okay this is pretty pedantic but it's potentially important!
The poison errata currently states (emphasis mine):
"When a model is hit by an attack with Poison # or affected by an Ability with Poison #, increase the number of Poison Tokens the model has to the # indicated either after resolving the attack, or as indicated by the Ability. Each time the model begins an activation it suffers 1 Wd per Poison Token it has, and then discards one Poison Token."
The way I read this, is that it takes each Poison Token causes 1 Wd individually. Thus, something with Object 1 that has 2 Poison Tokens on it would take 2 Wds when it activates. Similarly, a model that is Hard To Kill with 2 Wds remaining that has 2 Poison Tokens on it would die when it activates - the first Poison Token would cause 1 Wd, reducing it to 1 Wd, and then the second Poison Token would cause 1 Wd, reducing it to 0 Wd, killing it.
Now, if the intent is that it that it is all applied in one go, the bit I've highlighted in bold should probably be worded differently to make this clear. Perhaps something along the lines of "Each time the model begins an activation, it suffers # Wd, where # is the number of Poison Tokens it currently has, and then discards..."