Adding data to a table, from another table..reverse vlookup??

[Speshul]

Title not long enough. My problem:

I have 2 tables. One of them is large, very large, and contains a lot of information sorted by date for the entire year.

The smaller table is a full of a combination of vlookup/hlookup formulas, which I am using to show a 'summary' of the last few weeks only, for human digestion.

What I want to do is use the small table, or a 3rd table if needed, as a data entry point for the large table.

I am including a very stripped down version of what I'm working with. The actual sheet has these tables on separate tabs.

To make this difficult, I would love to do it without using macros/vba code, I'm trying for a non-macro enabled workbook, IF it is possible.

Thanks for lookin!