The big event on Holy Saturday is the blessing of the Easter baskets - "Swieconka".
The contents of a Polish Easter basket might include, but not be limited to, the following items:
Salt, butter, sausage, ham, eggs, bread, cheese, bacon, horseradish, and a candle.
These are all things that one would expect to be consumed the following day - Easter Sunday. Except for the candle. The candle would be used for religious devotions as necessary throughout the year.