Tables have incorrect padding when document has no H2 headings

[eric-schneider]

If a document has no second level headings (only a page title), paragraphs and tables appear too close together. I only tested tables, so there's a chance this issue affects the padding around other block types as well.

A basic table you can test with:

[cols="3*"]
|===
|test |test |test

|test
|test
|test

|test
|test
|test
|===