The symbolism that we find in Oscar Wilde's The Importance of Being Earnest is mostly situated around the items that constitute the different ways in which Jack and Algernon indulge in their double lives. One of these symbols is food, as well as its extravagant and careless consumption.
We find that both Algernon and Jack's alter ego, Ernest, have a penchant for over-indulging at expensive restaurants only to leave the bills unpaid for.This causes in Jack a sense of joy, as if being "bad" was a goal of his. This is significant because Ernest (when in the country living as Jack) is a model of good manners and responsibility, as he is in charge of the manor entailed to him by his adoptive father, and because he is also in charge of Cecily, who is his ward.
Therefore, food is a door to freedom for Jack and Algernon that shows extravagance at its best: Run bills, enjoy your meals, and do not pay. That is the life of the true so-called rich in Victorian England: A group of people that lead double lives and indulge in extravagances.
Algernon: You have invented a very useful younger brother called Ernest, in order that you may be able to come up to town as often as you like. I have invented an invaluable permanent invalid called Bunbury, in order that I may be able to go down into the country whenever I choose. Bunbury is perfectly invaluable. If it wasn't for Bunbury's extraordinary bad health, for instance, I wouldn't be able to dine with you at Willis's to-night, for I have been really engaged to Aunt Augusta for more than a week.
Food also appears in the showdown between Cecily and Gwendolen, when the girls use tea, cake, bread and butter, and sugar as symbols of power in society. Whoever used one thing would certify her power over the other.
GWENDOLEN:You have filled my tea with lumps of sugar, and though I asked most distinctly for bread and butter, you have given me cake. I am known for the gentleness of my disposition, and the extraordinary sweetness of my nature, but I warn you, Miss Cardew, you may go too far.
CECILY:[Rising.] To save my poor, innocent, trusting boy from the machinations of any other girl there are no lengths to which I would not go.
Furthermore, as the ladies discover that neither Jack nor Algernon are the "Ernest" that both girls think that they are engaged too, they take off the tea and cake battlezone and storm inside the house expecting to be chased by the men. Unfortunately for them, not only are they not followed, but...the men end up eating their food.
JACK:I say it's perfectly heartless your eating muffins at all, under the circumstances.Therefore we see how food plays an important role in the symbolism of the play, especially in the way that it bonds and divides the characters by social rank (bread and butter being more "fashionable" than cake) and how it unites them in extravagance and excess.
ALGERNON:When I am in trouble, eating is the only thing that consoles me. Indeed, when I am in really great trouble, as anyone who knows me intimately will tell you, I refuse everything except food and drink. At the present moment I am eating muffins because I am unhappy. Besides, I am particularly fond of muffins. [Rising.]
JACK:[Rising.] Well, that is no reason why you should eat them all in that greedy way. [Takes muffins from ALGERNON]