This gospel story causes one to meditate on two aspects of Christian life, action v. contemplation, prayer, and study.
1. Martha is the person who in their household is burdened with hospitality. They apparently have invited Jesus to come to dinner and someone has to cook, and make things ready, then clean. In a rich household that would be done by servants but not here. Because women traditionally have had clearly defined roles, then they would usually have had the role Martha is engaged in here. One would think that she would be helped by other women in the household and this is perhaps one reason she complains to Jesus. Another issue is women did not in Jewish culture engage in religious study and debate, so their may also be an unstated criticism here that Mary is doing something unseemly. Jesus does not agree.
We should note that Jesus does not say to Martha that she should stop what she is doing. He does not say that hospitality and service of others is somehow wrong, in general, or in this instance. After all, there are a number of servant stories in the gospel (Matthew 20:26; Matt 25:14-30). He did repeatedly say we are to love one another, and this is what Martha is doing. She is showing love by her work, her activity. However, this is not the only way we love and serve God, and it is the result of our conversion which comes after the knowledge of who God is, that He loves us and wants our love for others. So some knowledge of God is also necessary.
2. Mary is listening to God by listening to Jesus. This is something God has specifically commanded Luke 9:35; Mark 9:7; Matthew 17:5; John 5:25, and will reward. If we do not hear the Word of God, and reflect then we will not be Christian. Many people have been baptised, but there is no evidence of it in their lives, they are at best "cultural" Christians. All people need to have a conversion experience where in they discover Christ for themselves and respond with faith and commitment. Then we act on our faith.
When Jesus says that Mary has choose the better part he does not actually say that this is always better than love-in-action. It is better for this person in this situation. Actually, looking at both in light of the whole gospel it means both are valuable and (I think) both are needed in the church and in each individual Christian life. Some time is needed for prayer and study so we understand what God wants of us. Some time is needed to merely be in God's presence, and some time is needed to hear Him, especially to try and hear his guidance on the decisions and problems of life and work in His name.
3. In this light, the method for prayer and life used by Benedictines and others would perhaps be a good rule for us all. It is Lectio Divina. This is a method that combines these elements in a way of life called Ora et Labora, prayer and work.