Manage multiple leads from same contact

Eloqua tool is quite new to me, hoping i would receive an elaborate explanation or resources/materials for reference for my query.

I have forms hosted on an external site, these when submitted, and i receive enquiries/leads for products in i) different categories, ii) different regions and iii) different vendors, these form submissions are received in contacts object, creating one contact and are replaced on the same contact with the latest information of product. and i lose the other submissions in contact object in Eloqua. What is the best practice to capture such submissions?

Do i have to create a new object with 1:m relation to contact object? and then send this info as lead to sales cloud or what's the best solution? please advice.