Hi Naveen,
In column "parent" of tab "structure", this value is the object up the project hierarchy from the current object, i.e.;
- parent of project header is project header
- parent of first level element is project header (e.g. parent of a phase or task directly under the header is the header)
- parent of a second level element is the first level element to which it is assigned (e.g. parent of a task under a phase is the phase)
- etc.
As for the question about tables, I'm not sure if it is related to the t-code DPR_DX_PROJECT, and I'm sorry to say that there is no straightforward information about the whole table structure of Project Management.
However, you can run report DPR_GUID_ANALYZE with a GUID of a object in cproject. Then, you can find a list of tables. I hope this information is helpful.
Best regards,
Kim