Legitimate Office 2019 Home & Business keys can be found for $40–$60 on authorized resellers (not eBay random sellers). Then download the official 3.5 GB installer once—this is the safest.
Lossless compression algorithms—like LZMA (used in 7-Zip) or DEFLATE (used in ZIP)—operate on a fundamental principle: they remove statistical redundancy. A text file compresses well. A spreadsheet full of zeros compresses well. But the core components of Office 2019—DLLs, executables, system fonts, spell-check dictionaries, and the vast libraries for rendering Word documents or Excel charts—are already optimized binaries. Download Microsoft Office 2019 Highly Compressed
You cannot compress 3.5 GB of unique, non-repetitive binary code into 200 MB without losing data. Microsoft already uses CAB (cabinet) and MSI compression. Any third-party repack that claims 85%+ compression is almost certainly fraudulent. A downloadable installer that downloads the rest later