Most "51-pin LVDS" cables and panel-side connectors are based on the or FI-RE51HL series.

The extra pins are required to carry additional differential clock and data lanes to handle the massive bandwidth required for these high pixel counts. AliExpress Anatomy of a Common 51-Pin LVDS Pinout must always refer to your panel's specific PDF datasheet

You're looking for the pinout datasheet of a 51-pin LVDS (Low-Voltage Differential Signaling) connector. LVDS is a signaling standard used for high-speed data transmission, commonly found in display interfaces, such as LCD monitors, laptops, and automotive displays.

– Multiple ground pins for signal stability and shielding.