Populate Fields Using Data From Different Tables?

need to create a database for work. there would be a way to select an id based on a previous table and have parts of it populate in this new table.

For example:

Table A - Webinars (Webinar ID, Webinar Title and Client)
Table B - Sessions (Session ID, Date, Webinar Title, Time, Facilitator, Session Occurred, Reason, Conference Call) [Webinar Title I used a look up field and just select the corresponding Webinar Title and it works nicely]
Table C - Users (User ID, Status, Prefix, Last Name, First Name, Email Address, Component, Role and State)
Table D - Registrants (User ID, Session Date, Webinar Title, Attended).

So in Table D I would like to add Role and Component, so when I select User ID #1 the Role and Component Field populate with the info based on Table C.