Pixel grid

We want to build a webpage that is a grid of 1000 x 1000 tiny “cells” . Each cell is 10 pixels by 10 pixels. Our people can upload a picture that is square (same height and width). They can request which cell they want, and can then upload a picture to their ‘cell’. When viewing the grid, as your mouse goes over each cell, it pops up a box with the full box and some text