I personally believe that Fred Seward had his stateroom on E-deck. This is an article with some of Seward's comments:
'Frederic K. Seward, who sat next to W.T. Stead at the Titanic's saloon table, told of the veteran English journalist's plans for his American visit. His immediate purpose was to aid in the New York campaign of the Men and Religion Forward Movement. "Mr. Stead talked much of spiritualism, thought transference and the occult," said Seward. "He told a story of a mummy case in the British Museum which, he said, had had amazing adventures, but which punished with great calamities any person who wrote its story. He told of one person after another who, he said, had come to grief after writing the story, and added that, although he knew it, he would never write it. He did not say whether ill-luck attached to the mere telling of it." "After our conversation, we both went to the gentlemen's smoking lounge, where we finish the evening with cigars". Stead also told, Seward said, of a strange adventure of a young woman with an admirer in an English railroad coach, which was known to him as it happened, and which he afterward repeated to the young woman, amazing her by repeating everything correctly save for one small detail. "At around 10:30, I went down to my cabin, a few decks down, to go to sleep. An hour later, I felt a long scaring noise which aroused me immediatly" (...)
We cannot be sure if he was really on E-deck, but this is the impression Seward gave me.