You can specify values for border, cellspacing, and cellpadding in any of these sections:
[Tables]
[Attributes]
[TableAttributes]
However, if you specify values in more than one section for the same attribute (that is, values that apply to the same set of tables) you might get:
If you specify table border, cellspacing, or cellpadding values in the [Attributes] section, DITA2Go also includes the Border, Spacing, and Padding settings in the [Tables] section, resulting in duplicate assignments, which are not valid HTML. For these attributes, use only the [Tables] section.
If you specify border, cellspacing, or cellpadding values for a table or group of tables in [TableAttributes], even if what you list in [TableAttributes] does not include any corresponding attributes, for that group of tables DITA2Go ignores all of the following:
This means that if you set any of border, cellspacing, or cellpadding in the [TableAttributes]section, you must set them all; the entry in [TableAttributes] replaces all three. If you set border="0" and you want any cell padding or cell spacing, in the same [TableAttributes] entry you must specify greater-than-zero values for cellspacing and cellpadding. If you omit an attribute, DITA2Go writes no value at all for that attribute, in which case the browser default would apply.
[Tables]
Border=0
Spacing=3
Padding=6
[Attributes]
table= cellspacing="2"
For every table you would get a duplicate assignment for cellspacing:
<table border="0" cellspacing="3"
cellpadding="6" cellspacing="2">
[TableAttributes]
FormatA= border="2"