The word shrove comes from the word shrive which means to engage the Sacrament of Confession where we receive Absolution (the forgiveness of all that we have confessed) from our Lord Jesus Christ.  Shrove Tuesday, then, is all about setting ourselves in the most appropriate direction heading into Great Lent.  

The tradition of the pancake supper comes from the physical preparation of those in the Church to enter into Lent.  In a time when eggs and fats as well as meats were put away and not eaten during Lent, those in the Church would rid their homes of all such foods.  The making of a pancake was a great way to use up these remaining foods so that the house was empty of such fare.  It was an emptying of something from the household.  So, families and communities would host pancake suppers in this preparation for Lent.

Source: https://www.saintpeterorthodox.org/single-post/2019/03/11/Shrove-Tuesday-312-6-PM---730