How many error tables are there in fload and Mload and what is their significance/use?

Answers: 

Fload uses 2 error tables

ET TABLE 1: where format of data is not correct.

ET TABLE 2: violations of UPI

It maintains only error field name, error code and data parcel only.

Mload also uses 2 error tables (ET and UV), 1 work table and 1 log table

1. ET TABLE - Data error

MultiLoad uses the ET table, also called the Acquisition Phase error table, to store data errors found during the acquisition phase of a MultiLoad import task.

2. UV TABLE - UPI violations

MultiLoad uses the UV table, also called the Application Phase error table, to store data errors found during the application phase of a MultiLoad import or delete task

Apart from error tables, it also has work and log tables

3. WORK TABLE - WT

Mload loads the selected records in the work table

4. LOG TABLE

A log table maintains record of all checkpoints related to the load job, it is essential/mandatory to specify a log table in mload job. This table will be useful in case you have a job abort or restart due to any reason.