I'm a beginner, studying Data modelling as part of my course. I'm having trouble understanding Normalisation. How can i improve?
Just looking at an example of a table is a wrong way of normalizing. You should understand the meaning of the fields to properly normalize. For instance you should know if the salary is the same for all the persons that have a certain role, or if it differs from person to person (in the above example we cannot know, since each role has only a person, so that both interpretations are possible).

To know the meaning of the properties you have two routes: either know the meaning of the elements of the domain, through a high level model of it, (for instance through an Entity-Relationship model or a UML model), or to have formalized this knowledge through the definition of the functional dependencies holding between the properties.

In your example there are two points that are not clear (that this that are not clear from the example table): is the salary related to a role or to a person? Is the Est. Time related to a project or to the fact that an employee works for a certain project for that estimated time? If the correct anwer to those question is the first one in both cases, your schema is correct (or normalized). Otherwise you must revise it.