Or in memories draped by the beneficent spider Or under seals broken by the lean solicitor
The fact that worms/arachnids are a key element of this reading is really fascinating—and it sort of seems to come out of nowhere. The spider, just as in these lines, is mentioned in the Webster reading, of course:
O men, / That lie upon your death-beds, and are haunted / With howling wives! ne'er trust them; they 'll re-marry / Ere the worm pierce your winding-sheet, ere the spider / Make a thin curtain for your epitaphs.
The "worm" is mentioned by Webster, too, though it is not brought up in Eliot's poem. However, it does share a common trait with a spider—silk: just as a worm can produce silk (i.e. the silkworm), so does a spider ("spider's silk.") Silk as a material may be too specific for what Eliot is referencing, but nonetheless, it can form the material for the "draperies" and the "seals" mentioned in these lines.
It's clear to see the depiction of contrast between each creature. On the one hand, the worm doesn't produce the silk for the draperies, the seals, the winding-sheets, or the curtains—but breaks them. In this way, the creatures may be shorthands for humans that deal with a body after death. A winding-sheet is a "a cloth in which a body is wrapped for burial" (Wikipedia). According to Webster, the worm quickly pierces this cloth—in a way, quickly breaking the period of rest for the dead—just as, per Eliot, the "lean solicitor" breaks the "seals." The worm is akin to the solicitor—that who manages the will/other documents of the dead.
On the other hand, the spider is "beneficent"—it is good, because it doesn't break but "drapes" and "makes a thin curtain" for the dead. One can look at what a drape is, exactly, in its purpose: drapes are often referenced to curtains, which are almost always translucent or opaque so as to block out sunlight. In like fashion, the "drapes" of "memories"—or the "thin curtains" over "epitaphs"—seek to block out the memories of someone who is dead; or blocking out the fact that they even lived a life (which is recorded by an epitaph). On the other hand, the spider can represent the most vile and evil of acts. As Isabel Su points out in a historical annotation, "male spiders basically trap/stalk sexually immature females to ensure that they are the first ones to mate with them, and then female spiders eat their partners after copulation." The theme of sexual violence is very present.
In addition, there's an interesting play between life and death here. The death, and the draping of memories, seems to erase the record that life was present at all. Instead, the solicitor—the worm—brings the dead "back to life" by invoking the memory that they even existed in the first place. Even more interesting is what this has to do with datta—with giving. Is the solicitor truly the giver of life even though all it gives are the "memories"? In some ways, this would be supported by the Bradley text: if life is merely an illusion, the only way for our souls to communicate would be if we were to believe, or remember, that they were present in the first place. The only way for one's life to truly have existed would be if other people saw it as such—if they were remembered.