Slessor, 18 and from Gateshead, beat Chris Wakelin 4-0 in the final round.
Last season he beat Ryan Day in the PTC event in Bulgaria and lost by the odd frame to Ding Junhui and Marcus Campbell.
"I learned a lot from those games," he said. "I practise a bit with Marcus and I think has helped me realise the standard I have to get to.
"I just want to make snooker my job and show people that I can play the game. My main goal over the next two years will be to gain experience and keep my place on the tour.
"The new structure for most of the ranking events is great because you only need to win a couple of matches to earn good money and ranking points."
Hertford cueman Miah, 19, Kidderminster player Page, 25, and Holland-on-Sea's Davies, 25, will join Slessor on the tour for the 2013/14 and 2014/15 seasons.