Page 51. " plump little cakes called petites madeleines "
Creative Commons Attribution Share AlikeMadeleines - Credit: Bernard Leprêtre

This is arguably the most famous passage in Proust, introducing the idea of 'involuntary memory'. Proust's inspirational experience occurred with a piece of dry toast and tea, but he changed the toast to a madeleine in Swann's Way. The shell-like shape of a madeleine has been compared to the scallop-shells worn by the pilgrims to Santiago de Compostela, who would have passed through Illiers (Combray) on their way to Spain, during Proust's childhood (hence its "severe, religious folds" on page 54). The madeleine is therefore a symbol of a 'pilgrimage' to the past.

See a recipe here.

Page 54. " the game wherein the Japanese amuse themselves "
Paper flowers
Creative Commons AttributionPaper flowers - Credit: Jacek.NL

These are called Japanese water flowers. They come in little packets, the contents of which unfurl enchantingly when dropped in water. 

Page 62. " as much respect as any Greek tragedian "

In In Search of Lost Time Françoise takes on the role of a chorus in a Greek tragedy, commenting on the actions of the main characters.

Page 68. " How I loved our church "
John Ruskin by Millais
Public DomainJohn Ruskin by Millais
Proust was an enormous admirer of the English art and architecture critic John Ruskin (1819-1900) whose work he translated into French. He conceived In Search of Lost Time along quasi-architectural lines, and at one stage planned to call parts of the novel after architectural terms, 'Stained-Glass Window' 'The Apse' etc, but dismissed it as being too pretentious. However, Ruskin's influence persists, such as in the narrator's passionate interest in church architecture.
Page 70. " like an enormous pack of cards of the kind planned to beguile King Charles VI "

It was thought that the card game tarot (similar to whist), which uses a special deck of cards associated in the U.K. with fortune-telling, was invented to amuse the medieval King Charles VI of France. This idea is based on the existence of three decks of playing cards painted by Jacquemin Gringonneur in 1392 which are now kept in the Bibliothèque Nationale in Paris. Tarot is now thought to have originated in the fifteenth century in Northern Italy.