I think solving previous year questions is one of the main parts of GATE preparations. Reading the concepts and being thorough in them is important, but concepts alone won't help you sail through. One needs to practice large number of good quality and GATE relevent questions from each topic. Now GATE previous year questions are by IISC and IIT professors, so obviously they are of great quality.
I think solving questions from all topics till year 2005 should be enough followed by subject wise tests and full tests.
They will improve one's problem solving skills, which reading concepts alone cannot do. This is also a good way of brushing up the concepts and making them clearer.
Try solving them all and also rvising the questions once or twice, atleast three months before GATE, so that you sufficient time to revise and take tests.
-- Madhurima Mandal
AIR 422 GATE 2019
