What makes me mistaken is that I've been using 24c02 and 24C04 that are addressed on only 1byte.
You'll say, the 24C04 can't be addressed on only 1 byte. But it is ! Well not really.
In fact, the address block is on 1byte, the 24C04 is seen as 2 devices (1 on 0x50 and 1 on 0x51), the A0 pin has no function (no connect) and there is a 9th bit somewhere that I can't yet understand how it works and where it is.
This means that a 24C04 is using 2 devices addresses !
Bigger I2C Eeprom have their block address coded on 2 bytes, that mean up to 64kB on the same device I think (24C512)
The link you gave previously talks about a 24LC1025 24LC1026 of 128kB !
Twice more addresses than 2^16 (2 bytes addresses possibilities).
Is it using the same trick as for the 24C04 ?
This is quite confusing to me indeed !