@VenkateswararaoK the links @Kamil Janeczek provided are worth a read. I don’t explicitly mention it, but unticking queryable on your datapage will make it appear in the list.
Business Outcome?
What are you trying to achieve by putting it in that list?
There are numerous pros and cons of doing this that should be considered.
Queryable datapages take full advantage of constellation feautures, non-queryable do not, so you may be creating other problems here.
This menu is for Admins only, so no business user can create insights from these.
Explore Data is optimised for self service. Enhancing the object’s virtual report definition for joins , embedded data or the new Insights calculations would provide more overall benefit, than handcrafting datapages for each specific reporting need.