So, bizarrely , these 5,000 year old clay balls were an important step on the way to humans developing writing.
The small balls , called tokens, were sealed in the larger, hollow, clay envelope.
The tokens were used as a form of accounting. Perhaps as payment or as a contract for goods. (In this case I'm going to assume it was for fish because of the design on the envelope) (I'm also assuming that two different denomination of tokens are being shown)
Anyway, after awhile they started inscribing on the outside of the envelope a tally of it's contents. Later they would dispense with the tokens all together and just keep a tally on clay. This is the beginning of Cuneiform.
Didn't know that did ya?