One possible significance of the line "To have squeezed the universe into a ball" from T.S. Eliot's poem "The Love Song of J. Alfred Prufrock" is that it is very possibly an allusion (or reference) to a much earlier work of literature, Andrew Marvell's "To his Coy Mistress."
The final section of Marvell's poem, in which the speaker finishes his three-part argument about the need to seize the moment and live life now, includes the lines "Let us roll all our strength, and all / Our sweetness, up into one ball." The wikipedia entry listed below says the following about possible allusions in Eliot's poem to Marvell's poem:
The phrase "there will be time" occurs repeatedly in a section of T.S. Eliot's "The Love Song of J. Alfred Prufrock" (1915), and is often said to be an allusion to Marvell's poem.Prufrock says that there will be time "for the yellow smoke that slides along the street", time "to murder and create", and time "for a hundred indecisions ... Before the taking of a toast and tea". As Eliot's hero is, in fact, putting off romance and consummation, he is (falsely) answering Marvell's speaker. Eliot also alludes to the lines near the end of Marvell's poem, "Let us roll all our strength and all / Our sweetness up into one ball," with his lines, "To have squeezed the universe into a ball / To roll it toward some overwhelming question," as Prufrock questions whether or not such an act of daring would have been worth it. Eliot returns to Marvell in The Waste Land with the line "But at my back from time to time I hear / The sound of horns and motors" (Part III, line 196).
Good allusions are often subtle and open to interpretation. One reader may see an allusion where another reader does not. In this case, though, an allusion seems very possible. The allusion makes sense. Eliot was a huge fan of the metaphysical poets (including Marvell), and Eliot's works are often filled with unlabelled references to other, older literary works.