I agree. Fellowship is appropriate at the church, but not during the Mass/Service. I always talk to my friends at church after Mass is over or before it starts. We also have coffee hour after Mass once a month. We have Sunday school too (for adults, it is Bible study).
We should never talk to anyone BEFORE Mass starts. That time should be reserved just for Jesus. We have to prepare for the Mass. We could say prayers intended to say before the Mass starts.
A Prayer Before Mass
Act of Oblation before Holy Mass
Prayer Before Mass
And even AFTER Mass we should FIRST pray and then we can talk to our friends.

I pray the
Saint Michael Prayer then I pray one of these prayers.
A PRAYER FOR AFTER THE HOLY MASS
LORD, Father all-powerful, and ever-living God, I thank Thee,
for even though I am a sinner, Thy unprofitable servant, not
because of my worth, but in the kindness of Thy mercy, Thou
hast fed me with the precious Body and Blood of Thy Son, our
Lord Jesus Christ.
I pray that this holy communion may not bring me condemnation
and punishment but forgiveness and salvation.
May it be a helmet of faith and a shield of good will.
May it purify me from evil ways and put an end to my evil passions.
May it bring me charity and patience, humility and obedience,
and growth in power to do good.
May it be my strong defense against all my enemies, visible and
invisible, and the perfect calming of all my evil impulses, bodily
and spiritual.
May it unite me more closely to Thee, the one true God and lead
me safely through death to everlasting happiness with Thee.
And I pray that Thou willest lead me, a sinner to the banquet
where Thou with Thy Son and Holy Spirit, are true and perfect
light, total fulfillment, everlasting joy, gladness without end, and
perfect happiness to Thy saints.
Grant this through Christ our Lord.
Amen.
A PRAYER FOR AFTER THE HOLY MASS
I Beseech Thee, most sweet Lord Jesus Christ, that Thy Passion
may be to me power by which I may be strengthened, protected
and defended.
May Thy wounds be to me food and drink by which I may be
nourished, inebriated, and delighted.
May the sprinkling of Thy Blood be to me an ablution for all my sins.
May Thy death prove for me unfailing life, and may Thy Cross be
to me eternal glory.
In these be my refreshment, joy, health, and delight of my heart;
Thou who livest and reignest forever.
Amen.
I wish EVERYONE would pray at least BEFORE the Mass; that way those that would normally talk before Mass would not distract me as I pray before the Mass. I think it’s inconsiderate of those talking before the Mass starts. At least if a person wants to talk before the Mass they should talk OUTSIDE the Church and not inside where some people are kneeling and praying before Mass starts.
The same goes AFTER the Mass. I wish all would pray after the Mass also. You can talk later OUTSIDE of the Church or at least talk quietly inside the Vestibule.