If you can combine your two tables in Access first, or do the whole job in access then it would be a better tool - especially if your report is large. However, for various reasons that option is not open to me. So my thoughts about excel based solution:
If you have a large report to populate then thousands of cells with vlookups can slow things down a lot. I do this a lot with multiple columns having lookups to other files. But I have a simple VBA assisted routine whereby I:
Set calculation manual,
Copy the formula down one column at a time (typically 6000 rows)
calculate that column only and convert to values before moving on to the next.
Set calculation automatic
The workbook containing the source data must be open or things could freeze. (Again, I have vba to open all linked workbooks).
(In the past I played a little with Data, get external data, new database query to set up a relationship and get the data from my two tables into a single table in excel but that didn't work efficientlt for me.)
Gavin