A family of Microsoft word processing software products for creating web, email, and print documents.
Your description suggests your table has numerous cells containing paragraphs formatted with the 'keep together' and/or 'keep with next' attributes and, perhaps, your header row lacks those. Try removing those attributes from the entire table (except, perhaps, the header row). If you need to ensure cells aren't split across page breaks, uncheck the table's 'allow to break across pages' row option, for all rows.