Paid study leave is available to each trainee throughout their training programme in addition to holiday entitlement. It is intended to allow trainees to address areas of professional development relevant to their chosen career that will enhance the learning and experience from their training programme. A certain amount of funding is available too for specific expenses incurred during this leave. The amount of money available may vary but will be know by your locality programme office. So it is intended to address your personal needs.
Unfortunately the leave is subject to conditions and the notes from this link hopefully lay these out clearly. It is also necessary to point out that in many specialties including GP some of this time will be apportioned to study modules which are integral to the post. Where this applies, the modules have been provided after consideration of the needs of trainees historically. They enhance the locality programme's provision and they are also evaluated and monitored to ensure that the trainees' experience continues to be rewarding.
The main point is that you should plan well ahead with your educational supervisor and programme director but consider this as an opportunity for you to enrich your training experience. The notes from this link should be clear, but if you need any further clarification, please seek it from your locality programme.