Participants: Tanaka, Suzuki, Sato, and so on (rest omitted).
What you need: notebook, pen, eraser, and so on.
以下 means 'the following' or 'less than', but in the phrase 以下略 it combines with 略 (abbreviation) to mean 'the rest omitted'.
Compound of 以下 (ika, 'below' or 'the following') and 略 (ryaku, 'abbreviation' or 'omission'). The reading いかりゃく is a standard on'yomi combination.