I'm sorry if it wasn't clear. These are appendices to a document that will be published by a government contractor. Format requirements are that appendices have a letter (B in this case) and the individual pages are numbered sequentially in that appendix. In the case I was asking about, we're using 11x17 paper to print oversized figures and/or tables. The format guidelines suggest using B-1/B-2 to compensate for the size of the paper when you're going to duplicate a two-sided document. It's complicated, but "normal" for what we're doing.

It doesn't really matter now, though, since we decided to (with this particular table anyhow) just use B-1, B-2, etc. So it's solved, but I did have to work around the issue since there doesn't seem to be a way to split a table without actually breaking it into two tables.