As far as I know, there has been no detailed examination of column layouts in New Testament manuscripts -- at least in any context relating to textual criticism. But it seems likely that manuscripts were written in columns from the very earliest days -- scrolls, after all, had to be written in columns. The Greek word for a column is σελις, although this the word originally meant instead the space between the columns.
It is often stated that, with the exceptions of ℵ and B, all continuous-text New Testament manuscripts are written in one or two columns. This is not quite true (048 and 053 are also in three columns, as is the minuscule 1957 and, of necessity, the trilingual minuscule 460 -- and of course there are many commentary manuscripts which use irregular page formats), but not far from the mark. The following table shows, by century, the number of manuscripts with one, two, three, and four columns. (Note: Manuscripts must be substantial enough for the determination to be certain.) For the first five centuries, the manuscripts themselves are listed. The percentage of manuscripts in each category is also listed. The data is as given in the first edition of the Kurzgefasste Liste (note that paleographic estimates in the Liste are not always reliable, and this list is only approximate).
Century | Number of Columns | |||||
---1--- | ---2--- | ---3--- | ---4--- | Scroll | ||
I/II | 𝔓46 𝔓66 | |||||
III | 𝔓45 𝔓47 𝔓72 𝔓75 0212 0220 0232 | 𝔓13 | ||||
IV | 0162 0169 0176 0181 0189 0206 0228 | 057 058 0171 0185 0207 0214 0221 0230 0231 | B | ℵ | ||
V | C I W 059 061 069 0163 0172 0173 0174 0175 0182 0217 0244 | A Q T 062 068 0160 0165 0166 0201 0216 0218 0219 0226 0227 0236 0239 0242 | 048 | |||
VI | 13 (24%) | 42 (76%) | ||||
VII | 7 (28%) | 18 (72%) | ||||
VIII | 9 (39%) | 13 (61%) | ||||
IX | unc | 17 (38%) | 27 (60%) | [053] (2%) | ||
min | 9 (75%) | 3 (25%) | ||||
X | unc | 8 (53%) | 7 (47%) | |||
min | 89 (85%) | 16 (15%) | ||||
XI | unc | 1 | ||||
min | 283 (81%) | 68 (19%) | ||||
XII | 461 (87%) | 69 (13%) | ||||
XIII | 458 (89%) | 59 (11%) | [460] | |||
XIV | 454 (91%) | 45 (9%) | ||||
XV | 193 (90%) | 21 (10%) | [1957] | |||
after XV | 145 (88%) | 19 (12%) |
It is sometimes stated that the reason ℵ is written in four columns is that this gives the appearance of a scroll. It should be noted, however, that the papyri are usually in one column, so Christians had clearly already abandoned the "scroll look" before ℵ was written. It seems more likely that ℵ, which is one of the largest uncials known (indeed, based on the data in the first edition of the Kurzgefasste Liste, it is as presently bound the largest uncial known), was written in four columns to keep the width of each column close to the standard column width found in other manuscripts.
It is also worth noting that 2-columns format was standard for uncials (57% of uncials are in two columns), and also very common for lectionaries, but while obviously acceptable, certainly not normal for minuscules (only 13% of minuscules have more than one column, and many of those are diglots). One may speculate that this has to do with readability. Uncials, particularly early uncials which lacked punctuation, word spacing, and breathings, were difficult to read. To reduce the stress of reading, scribes may have resorted to narrower columns. When the more readable minuscules became standard, scribes turned to the easier-to-copy-but-harder-to-read one-column format. (It is now known that there is an optimal column width for reading; a column which is requires the reader's eyes to move more than five or six times makes reading more difficult. Ancient scribes could not have known this, but they could well have sensed that narrower columns were easier to read than wide.)
Note that this applies only to Greek manuscripts. Other traditions will have
other histories. Indeed, Christopher de Hamel, A History of Illuminated Manuscripts, Phaedon, 1997, p. 91, states that "at the beginning of the twelfth century many manuscripts were still in a single column format, but by about 1170 manuscripts were generally larger and often in two columns." De Hamel does not say which manuscripts this applies to, but it appears to be Latin manuscripts (because he goes out of his way to ignore the very existence of anything in Greek). Still, it shows how different traditions differ: at a time when Greek manuscripts were, on average, reducing their number of columns, de Hamel finds an increase among the manuscripts in his sample base.