LibreOffice is a powerful all-in-one office suite for Windows and Linux that combines pretty much everything you need to increase workflow productivity. Portable version also available.
It embeds several applications, including Writer, the word processor, calculator, the spreadsheet application, Impress, the presentation engine, Draw, the drawing and flowcharting application, Base, an able-bodied database, and database front end, and Math for editing mathematics. You can create HTML files, tables, etc., with ease, and the suite will work with ODF (OpenDocument Format).
LibreOffice's functionality is also expandable with add-ons or extensions.