What is the purpose of the 150 Ohm resistors in series with the SCL and SDA lines in the DS2764AE?
These are series protection resistors on the I2C lines. SDA and SCL drivers are open-drain outputs, requiring a pullup resistor to generate a logic-high voltage. Series resistors RS are optional. These series resistors protect the input stages of the device from high-voltage spikes on the bus lines, and minimize crosstalk and undershoot of the bus signals.
Please see the article below for more informaton
https://electronics.stackexchange.com/questions/191866/series-protection-resistors-on-i2c-lines