Matrix 010, Grid 19 was a spatial designation for a region in Borg space.
In early 2374 it was the location of a major confrontation between the Borg and Species 8472 during their brief war.
Species 8472 annihilated the Borg in this confrontation, causing the destruction of 312 ships (including a number of Borg cubes), 8 planets and 4,000,621 drones. (VOY: "Scorpion, Part II")