Hi Tony,

Either

1) link or import the data to a temporary table and then use an append query
to move the data into the existing table, or

2) create an append query that uses the SQL  IN clause to get the data
directly from the worksheet and append it to the table.

Tony,

Go Files > Get External Data > Link Tables and follow the wizard to link
your spreadsheet, then make an append query on it. Alternatively, if the
 columns in the spreadsheet are in the same order as the fields in the
table and no other data manipulation is required, you could do a plain
coy in Excel and Paste in the table (in datasheet view, selecting a new
record).

HTH,
Nikos