In the VIEW and AREA dialogs, there are fields to customize some of the tag attributes. On the VIEW dialog there are the "Body Tag Add" and "Table Tag Add" fields, and on the AREA dialog there are the "Cell Tag Append" and "Table Tag Append" fields. On these fields, you can put attributes for the referenced HTML tag (<BODY>, <TABLE>, <TD>, <DIV>).
But these tags are not blindly added to the tag. The tags you put there are parsed, and actually can override HTMLButcher's generated ones, ensuring there is no duplicate attributes on any of these tags.
There is special handling for attributes named STYLE. These attributes have their own CSS attributes control, so if you add a STYLE attribute in any of these fields, the styles are parsed, and mixed with HTMLButcher's generated ones, again ensuring no duplicates.