Fuel Gauge Issue - Honda CRV 2008 - 65K miles

I have a 2008 Honda CRV , 65K miles on it ,the issue which i notice was though i do a full tank the fuel gauge drops down few bars within 30 miles which is unusual , any idea whats going on ?

Clarify your question. Does the Honda do this all the time and you consider it a problem or has it done it just this time and you are concerned?

Despite some much advancement in car technology the fuel gauge still remains a very rough approximation of the water level in an ocean, so some error is expected. Not sure what your exact problem is.