IP Table and routing table
 

Could anyone tell the difference between IP table and routing table in detail?

Well they're just basically *totally* different things. the routing table defines what local devices to talk to in order to get to remote locations, whereas an iptable table defines rules to process the traffic, either blocking / permitting or modifying it it someway, most commonly through natting. outside of some more esoteric packet marking that iptabels can do, that you're unliekly to exver need, the two really have nothign in common.

Note that this division is also how every firewall I've ever used deals with things, how to get somewhere is always separate to being allowed to go there.