You can highlight the column and choose Worksheet: Reduce Rows. Set as follows: Reduce Method: Delete N rows, then skip M rows. Delete Rows: 2 Skip Rows: 1 Starting Row to Delete: 1 Output: New Column.
Some other reduce data methods in Origin Worksheet: Remove Duplicate Rows which works on the whole worksheet. Analysis: Data Manipulation: Reduce Duplicate X, Reduce by Group, Reduce to evenly spaced X which can help reduce xy dataset.