The main subplot is a romance, with Persse McGarrigle chasing Angelica Pabst, a PhD student who is herself studying Romance. When propositioned she replies by quoting Keat's The Eve of St Agnes, and poor Persse is left wondering what her reading of the poem is. All sorts of interesting literary tidbits are provided — among other things we discover that the Japanese translation of The Merchant of Venice is titled "The Strange Affair of the Flesh and the Bosom".
Small World is great entertainment. You probably need some understanding of trends in modern literary criticism and a reasonably extensive knowledge of the canon of English literature to appreciate it fully, but the reader lacking that will still enjoy it as pure comedy.