Here's why:
* Seeking Escape: The speaker is immersed in books, likely ancient and forgotten texts, as a way to escape the painful reality of his loss. He's seeking solace and distraction in the written word.
* Memory and Reflection: The act of reading also allows the speaker to delve into his own thoughts and memories. He's likely revisiting past moments with Lenore and grappling with the pain of her absence.
* A Symbolic Representation: The speaker's engagement with literature can be seen as a symbolic representation of his intellectual pursuits and his attempt to understand the mysteries of life and death.
The poem's opening lines emphasize the speaker's weariness and the desire for escape:
> "Once upon a midnight dreary, while I pondered, weak and weary,
> Over many a quaint and curious volume of forgotten lore—"
The speaker's immersion in "forgotten lore" further highlights his yearning for something beyond his present sorrow. This literary world offers a temporary refuge from his grief.