Normally in UK master degree is one year course. There is hardly time for a serious job. But for students there is number of maximum hours that they allow to do part time jobs. Depending on uni normally they provide jobs inside the uni up to the maximum hours allowed for a student. There is a minimum wage for an hour and normally that minimum is paid for unskilled work eg cleaning, security, library assistance etc.
During the Christmas vacation there is possibility of finding more work. I do not know whether there is strict rule as to maximum hours of work as in Austarial, where our srilankans complain if you work exceeding the allowed period!(and the person will be expelled from Austalia if found true!) It was not there in UK but find out it and any event be careful.
Again in the summer brake there is time for a job and after completing the degree they allow another 3-4 months extension of visa(this is for referred students but normally they allow anybody who apply) this is the time for a job and earn if you have got through the exam without any referrals as this time will be free for you .
My advice is to make best use of the scholarship and study and think about a job there after. Who knows if you do well they might offer a permanent job!