Note:
The first split paragraph is the third song of the Five Songs of King Wulfharth.
The second page seems to be a design document about the layout of Septimus Signus's Outpost, with three giant letters in the Magic Script reading "O L F" and the star of Lakshmi diagram containing a Q at the center, encircled clockwise (starting at the top) with the characters 2, 1, Z, X, Y, W, V and U.
The third page seems to be written in Portuguese ("conduziu o aqui a este", meaning "led here to this") and also talks about Septimus Signus ("Skyrim. Septimus vive em" meaning "Skyrim. Septimus lives in"), and might be a shorter excerpt of the previous design document. It also has a spiral showcasing the golden ratio, containing the letters S, T U, V and W (starting from the outside of the spiral). The text at the bottom remains undeciphered.
The fourth page is a diagram with three letters in the Magic Script (F, R and P) and yet undeciphered text all around.
The fifth page contains three texts, the first of which "Finally, one dragon (that we know of) decided to join the human side — this was Paarthurnax. He’s the Prometheus to the proto-Nords — he taught them to use the Voice. This turned the tide, and the proto-Nords continually defeated Alduin and the dragons and" reads like a design document about Paarthurnax, followed by a text in the Magic Script saying "Alduin's civilizaton was the Dragon Cult of Atmora. He's basically the Dragon God on earth. The dragon high priests are his acolytes and everything is ordered." and a final text "everything else. Alduin was the creator of dragon civi[liz]ation — the Firstborn and the smar[test.] [D]ragons were attracted to Human oppo(?) [b]ecause they shared the Human (?) of the world as a gift o[f] gods (even Alduin knows Akatosh created Mundus). (Or humans learned their" which seems to be a continuation of the deciphered text from the second used page of the Shalidor's Insights and to explain that either dragons found themselves ruling over humans because they shared a similar worldview, or that humans learned that worldview from dragons.
All of these read less like in-game texts meant to be read by the player and more like design documents used during game development and later repurposed as filler-words for obscure ancient texts with unreadable fonts that we were never really supposed to decipher.
Page 1:
"The third song of King Wulfharth tells of his death. Orkey, an enemy god, had always tried to ruin the Nords, even in Atmora where he stole their years away. Seeing the strength of King Wulfharth, Orkey summoned the ghost of Alduin Time-Eater again. Nearly every Nord was eaten down to six years old. Boy Wulfharth pleaded to Shor, the dead Chieftain of the Gods, to help his people. Shor's own ghost then fought the Time-Eater on the spirit plane, as he did at the beginning of time, and he won, and Orkey's folk, the Orcs, were ruined. As Boy Wulfharth watched the battle in the sky he learned a new thu'um, What Happens"
Page 2:
"The current home of Septimus Signus. From the exterior, it’s a normal-looking iceberg that happens to have a hatch on it.
In the center of the iceberg, though, is a large Dwemer lockbox: Septimus has carved a cave into the iceberg so that one side of the lockbox essentially makes up a wall of the cave.
The iceberg was created around the lockbox by some unknown person within the last few hundred years. This person came across the Oghma Infinium, recognized it as a tool of evil, and sealed it away in the lockbox/iceberg combo so that the world would be safe from its influence.
It does not need to be a large space, but there should be a space between Septimus’s living area, which he shares with the lockbox, and the exit where the player can be out of sight — Hermaeus Mora will appear to him there."
Page 3:
"QACONDUZIUOAQUI AESTEP"
"QESKYRIMSEPTIMUSVIVEEMU"
Page 4:
Page 5:
"Finally, one dragon (that we know of) decided to join the human side — this was Paarthurnax. He’s the Prometheus to the proto-Nords — he taught them to use the Voice. This turned the tide, and the proto-Nords continually defeated Alduin and the dragons and"
"Alduin's civilizaton was the Dragon Cult of Atmora. He's basically the Dragon God on earth. The dragon high priests are his acolytes and everything is ordered."
"everything else. Alduin was the creator of dragon civi[liz]ation — the Firstborn and the smar[test.] [D]ragons were attracted to Human oppo(?) [b]ecause they shared the Human (?) of the world as a gift o[f] gods (even Alduin knows Akatosh created Mundus). (Or humans learned their"