In the Braille Formats we encounter all kinds of ways to shorten row and/or column headings and/or entries, but not really a set guideline that says whether we can or cannot use extra columns in a simple 2 column table to fit it on one page or not.
I am sending a PDF of the table in question and other options as possible ways to transcribe it.
Please let me know if there are rules or flexibility on this matter, and any opinions of which way would be preferable if the other options are possible. If so, do I need a TN about changed format?
I was looking at BF 11.1.1, 11.2.5e, 11.2.6c, 11.4.4, and 7.3.1 for guidance.
Braille readers read across the page - changing a table as you have suggested may make it actually harder for the reader to understand and follow. There are no rules in Braille Formats that allow for changing a single column table to multiple columns. Space-saving is not the issue that it once was. All that to say that no, it is not recommended that a table be changed from a single column to multiple columns.