Regarding pipe tables, the pandoc manual reads as follows:

If any line of the markdown source is longer than the column width (see –columns), then the table will take up the full text width and the cell contents will wrap (…)

The wording on this is quite unclear:

• What is meant by “any line of the markdown source”? Does that include lines which are not part of the table itself?
• What is meant by “the full text width”? Is it the width in the markdown source or the rendered version? Why should this have an impact on the table width?