Repeat a Header Row
The Problem:
Today's report has an ugly six-page table in it. I'm cleaning it up, and every time I make an editeven applying or removing formattingthe rows bounce from one page to the next. That means the heading rows on the second and subsequent pages are now in the wrong place. I moved them back the first time I noticed it, but they keep jumping around. I guess I'd better leave 'em until I finish editing.
The Solution:
If they're moving around, they're not real heading rows: they're just normal rows formatted to look like heading rows. Word can automatically repeat one or more heading rows for you when the table goes to a second or subsequent page. Set up the row (or rows) on the first page, select it (or them), and choose Table 
Heading Rows Repeat. When rows walk from one page to another, Word keeps the header row or rows in the right place.