Ancient and almost forgotten (wedding) custom is to not deny a traveler from your doorstep. In the times before hotels and such, a traveler would depend on the kindness of strangers who would let them sleep in their home, share meager food in exchange for tales of their travels or small gifts. One of the most ancient rights are so called guest rights, hospitium or xenia, divine right of guest and divine duty of host. To break those was to invite punishment from the gods. Even Odyssey has Odysseus disguising himself as a beggar.
In the later times, the custom wasn't so carefully observed. Yet, there was still a remnant of that belief and it went as follows: When people celebrated wedding or christening, it was considered a bad luck to refuse anyone wanting to join in the celebration. There are multiple stories and legends of kings, gods or fairies wandering around disguised as beggars and asking for alms. If the host received them gracefully, they would get a blessing from the god. If they mistreated the powerful person disguised as beggar, a quick, usually magical punishment such as curse would follow. See for example Beauty and The Beast or Sleeping Beauty. The more important the event (Birth of a child, wedding, even funeral), the more likely that supernatural being would try to join as an uninvited guest, disguised as vulnerable beggar.
Thus, beggars and generally poor people would be very happy when somebody celebrated a wedding, because they could join in the celebration and eat and drink for free. The longer the wedding celebrations, the more relieved they were of their poverty and hunger, if only temporarily. And if the host was rich, the food would be great too.
Another reason for that belief was this quote from the Bible, Luke 14:13-14
"13 But when you host a banquet, invite the poor, the crippled, the
lame, and the blind, 14 and you will be blessed. Since they cannot
repay you, you will be repaid at the resurrection of the righteous.”"
For a modern look at that trope, lookup "The Mystery Knight" by George RR Martin in which a hedge knight joins wedding celebrations and tournament of lord of the lands they are passing through, along with a few more hedge knights.
Couldn't quite find confirmation of Tudor customs, except that Henri VIII organized multiple feasts all over the city of London and tournament when he married. It might be another status symbol: I am so rich and generous. I can show it by feeding the poor.
Found another custom though.
Another custom is when the couple left the church. Then the groom (or groom's brother or a godfather) would throw small coins to the mass gathered in front of the church to spread joy. And couples in southern France still throw coins when they leave the church as a throwback to a more ancient tradition, where child beggars were allowed to harass newlyweds. They'd often prevent them from leaving the church grounds until the groom paid them to go away.
Customs with coins