How can I use formulas in MC34063 DC-DC converter datasheet?
It is a very unusual looking specification table because it isn't a spec table. You are looking at a table that represents the design calculations in a step by step format. 

You start by plugging your known values into the first equation on the right. This gives you the resulting term and value on the left. You then take this new value of the term and plug it into the next or subsequent formula on the left when it is called for. You continue this sequence through the entire table and the result is you know all the required component values and operating parameters.

It is an unusual way of expressing design equations but it is eloquent in its  methodicalness and brevity.