When did small bite-sized portions become the norm for Communion?

The sources given in that Wikipedia article certainly suggest that the Agape love-feasts and partaking of the bread and wine at the Lord’s Table were separated sometime between the latter part of the first century and 250 A.D.

[4] Walls, Jerry L.; Collins, Kenneth J. (2010). Roman but Not Catholic: What Remains at Stake 500 Years after the Reformation. Baker Academic. p. 169. ISBN 9781493411740. So strong were the overtones of the Eucharist as a meal of fellowship that in its earliest practice it often took place in concert with the Agape feast. By the latter part of the first century, however, as Andrew McGowan points out, this conjoined communal banquet was separated into 'a morning sacramental ritual [and a] prosaic communal supper.'

[5] Davies, Horton (1999). Bread of Life and Cup of Joy: Newer Ecumenical Perspectives on the Eucharist. Wipf & Stock. p. 18. ISBN 9781579102098. Agape (love feast), which ultimately became separate from the Eucharist ....>

[6] Daughrity, Dyron (2016). Roots: Uncovering Why We Do What We Do in Church. ACU Press. p. 77. ISBN 9780891126010. Around AD 250 the lovefeast and Eucharist seem to separate, leaving the Eucharist to develop outside the context of a shared meal.

Note b says: “Several sources mention a prohibition of the agape by the Second Council of Orleans in AD 541. Sources are provided:

[31] The Gospel Advocate, vol. 3, 1823

[32] Cole, Richard Lee, Love-feasts: A History of the Christian Agape[dead link]

[33] The Antiquaries Journal, Oxford University Press, 1975 Source: https://en.wikipedia.org/wiki/Agape_feast

I have found some information on the views of Baptists with regard to communion, but nothing specific about communion being separated from a meal between 70 and 250 A.D. I hoped the following article would shed light on this subject, but I was unable to access this document:

The Lord’s Supper in Baptist History by W. Morgan Patterson, Published 1 February 1969: https://journals.sagepub.com/doi/abs/10.1177/003463736906600104?journalCode=raeb

An official Baptist source has this to say about changes that may have begun before the end of the first century:

Although the first Christians probably shared communion as part of a regular meal together, practice shifted towards celebrating it as a distinct act of worship in the congregation. This process was probably already under way in the New Testament itself (1 Corinthians 11:17-22). The earliest Baptist practice of sharing one loaf and one cup containing real wine shifted for reasons of hygiene and temperance to that of using cubes of bread or smaller loaves and small, individual cups of non- alcoholic wine. There is now a movement back in some churches to the undoubted practice of Jesus himself and of earlier generations of Christians of using a shared cup. Source: https://www.baptist.org.uk/Publisher/File.aspx?ID=168464&view=browser

Baptist preacher C. H. Spurgeon had this to say in a sermon based on Luke 22:19, preached in 1888:

“This,” simply “this,” and nothing more, and nothing less; bread, not a wafer; fruit of the vine, not the concoction of chemistry inflamed with fiery spirit. We use this fruit of the vine in a cup, and that cup not reserved, but partaken of by all. We have before us bread, and that not worshipped, as at the elevation of the host, but broken and eaten. The Lord and His disciples sat at a table and ate; it was a feast, and not a sacrifice; they reclined, and did not kneel. So would we do, because He has said, “This do,” and not something else. https://www.spurgeongems.org/sermon/chs2038.pdf

The sermon appears to suggest that Baptists in England shared wine from one cup and ate bread broken from a loaf. I can’t see them all reclining at a table, though. The Metropolitan Tabernacle in Newington, London, was not constructed to accommodate such an activity, especially when hundreds of people regularly attended. Another difference is that Jesus and his disciples ate unleavened bread at the Passover meal.

Interesting question, although I regret I am unable to access any primary sources. The information in the Wiki article on Agape feast is intriguing so thank you for sharing that with us.