why reception table is kept higher than normal

If You mean a Receptionist's Desk,say in a Hotel,it could be a psychological or cultural thing in that someone checking in or out would be bent over in a bowing position at a lower,or "normal" desk level,which would be taken as a Demeaning position in some cultures..the whole point of the Hospitality industry is to make the Customer feel wanted and respected,so everything possible to reinforce that will be done so as not to belittle or insult them..just my Opinion!

not quite sure but i guess its just because the receptionist will find it easy to operate.....wat i mean is, o write entries in the register or to attend phone calls..... it sometimes even appeals to the aesthetics as well the ergonomics... may be.. just a point of view