let users click on the timetable to select slots

[abhitrueprogrammer]

Is your feature request related to a problem? Please describe.
When selecting of slots can be done just by clicking on slots on the time table, why give out buttons? I get its asthetically pleasing, but we can either:

1. let that go
2. Allow users to select and deselect slots both ways

Describe the solution you'd like
Why not just allow user to click on the time table to select labs, theory slots, and grey out slots there only

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context