Greetings, according to the datasheet for the PCE-BSK 310 it is equipped with a piece counting function so it should be capable of weighing multiple pieces. Unless you need to build the device for some other purpose building your own should not be necessary.
We have a number of scales available in the following link specifically built for weighing and counting pieces. Specialty Equipment | Equipment | Electronic Components Distributor DigiKey, many of them should meet or exceed the specifications you requested. Please review the datasheets for more information.
Please note they are Marketplace products and as such are only available within the U.S. at this time. For more information on Marketplace products please see Digi-Key Marketplace - Site Help, Information and Feedback / Digikey.com Navigation and Terminology - Electronic Component and Engineering Solution Forum - TechForum │ Digi-Key
If you are outside the U.S. and these will not work for you I recommend Googling “counting scales” to find similarly equipped items that may be available to you.