Entries in tables, such as row header text, should be short, or they can present difficulties. For example, long headers could make it harder for our eyes to follow a row with short entries but wide skips. One approach to adding the necessary details while keeping the table itself short and crisp is using footnotes.
Instead of placing the notes at the foot of the page, it's a good idea to add the notes directly at the foot of the table. We also call them table notes. Some benefits of this are as follows:
While common footnotes are written at the page bottom to retain the text flow, text following a table is usually independent of that table. So there's no need to defer notes further down.
Tables can automatically move for better page breaks; their notes should stay together with the corresponding table.
Table notes can be independent of text footnotes. This saves headaches about keeping numbering in order.
Footnotes...