Create a normal select query - and put all your fields into the query.
Now change to SQL view and your query should look like this:
SELECT Jan1.fldDate, Jan1.field1, Jan1.field2
FROM Jan1;
Now update the SQL to look like this:
SELECT fldDate, field1, field2
FROM Jan1
UNION ALL SELECT fldDate, field1, field18
FROM Feb1;
This will paste Feb1 table onto the bottom of Jan1 table.
If you miss out the ALL clause then any duplicated rows are left out.
Each field must be in the same order, and must be the same data type. They can have different names and the final query will use the names of the first table.
If you use:
SELECT *
FROM Jan1
UNION ALL SELECT *
FROM Feb1;
Then each table must have the same number of fields.