Append Queries stacks tables on top of each other: the second quarter under the first, one region's export under another's. It matches columns by name, not by position. A column that exists in only one table still appears, with null in the rows from the tables that don't have it. So if one file says Qty and the others say Quantity, you get both columns, each half empty. Rename first, then append.
Append Queries adds the rows to the current query. Append Queries as New leaves the inputs alone and builds a new query, which is cleaner when several files feed one table.
Then turn off Enable load on the input queries (right-click them in Queries). They still feed the new query, but they don't become tables of their own in the model.