Questions about Acer Monitor Stand DUO up to 2x 32inch Monitors VESA 75x75 and 100x100

No, "payload 8kg" does not mean that both monitors together may only weigh 8kg. It means that each monitor that the monitor stand holds may weigh a maximum of 8kg. For your specific requirement, a desk mount for 2x 32" AOC monitors weighing 10kg each, the "Monitor Stand DUO up to 2x 32inch Monitors VESA 75x75 and 100x100" from Acer would not be suitable, as the payload per monitor is 8kg, which is less than the weight of your monitors.