Odysseus does not know the details of what is going on at home. His first partial understanding comes in Book 11 when the prophet Tiresias tells him of the wretched suitors at Ithaca. After the spirit of Tiresias departs, he speaks with the spirit of his mother, Anticleia, who also updates him on matters at home. Tiresias says:
"When you get home you will take your revenge on these suitors; and after you have killed them by force or fraud in your own house, you must take a well-made oar and carry it on and on, till you come to a country where the people have never heard of the sea and do not even mix salt with their food, nor do they know anything about ships, and oars that are as the wings of a ship. I will give you this certain token which cannot escape your notice."
A few books later Athena guides him to Ithaca. It is here that he finds out about the suitors in greater detail.
"There is your dinner friend, the pork of the slaves. Our fat shoats are eaten by the suitors, cold-heated men, who never spare a thought for how they stand in the sight of Zeus. The gods living in bliss are fond of no wrongdoing, but honor discipline and right behavior." 14.97-103
Here is a more direct quote reflecting Odysseus's hatred:
"Son of Laertes and the gods of old, Odysseus, master of land ways and sea ways, dissemble to your son no longer now. the time has come: tell him how you together will bring doom on the suitors in the town." 16.195-9