ST25DV04K-IER6S3 is fully decoded in your datasheet link. See section 11 - Ordering information, found on page 156. See EDIT
The other markings are most likely to be batch/date codes.
EDIT:
ST25DV = Dynamic NFC/RFID tag based on ISO 15693 and NFC T5T
04K = 4 Kbits
IE = I2C & GPO open drain, fast transfer mode & Energy Harvesting
R = VCC = 1.8 to 5.5 V
6 = industrial: device tested with standard test flow over - 40 to 85 °C
S = SO8N <-------Package.
3 = 28.5 pF
The second half is almost certainly the manufacturing site and date code, which will be different for every batch.
The two you have are probably 2018 week three and 2018 week 24.