There are digital scales for just about any weight. Personally I’ve worked with scales that go down to 0.1 mg, and scales that can do a complete truck, and various sizes in between.
Many of those scales come with digital displays, or even a printer for weight tickets, etc. That means they can all be read digitally, and that in turn means an Arduino can read them.
It’s just up to you to get the correct sized load cells, and the interface hardware to operate them. The easiest is for sure to go for commercial scales that have a TTL or Serial (RS232 or RS485 will be quite common) or other form of digital output, which you can directly read with your Arduino, and then do whatever you want with the weight info.