The MSc Psychology & Education (Conversion) is suitable if you:
a) don't have an Undergraduate degree in Psychology (but have a degree in another subject),
b) have an UG degree in Psychology, but one that isn't accredited by the British Psychological Society (BPS).
It's aimed at people for whom BPS accreditation is important - i.e. those who want to go on to try and train as a practitioner, such as an Educational Psychologist (which is a further 3 years study).
The MSc Psychology & Education (Conversion) has far more intensive teaching and learning, because it is a conversion degree, i.e. it promises to cover in a year all topics (and readings) that a 3 year BA course in Psychology would cover.
The MA in Psychology and Education would suit people who either have or do not have an undergraduate degree in Psychology, and for whom BPS accreditation does not matter. This course is not accredited by the British Psychological Society (BPS), which means there is more flexibility in course content. So this course would suit you if you:
a) have a BPS accredited undergraduate degree but wish to expand their knowledge about Psychology,
b) students who do not have a Psychology UG but do not intend to train as practicing Educational Psychology,
c) students who are considering further study/research careers, i.e. doing a PhD.
Other differences are: The MA Psychology & Education is a much larger cohort, and likely will have more international students. The MA Psychology & Education syllabus covers more critical content.