Regardless of how you connect your data to eagle.io, you may find yourself in a situation where you have a spreadsheet full of time-series data that you want to apply to an existing Data Source. Rather than using a data transport to transfer your file, you can upload it directly using the Historic Import Wizard.
Before you can import data, it will need to be in CSV format; simply make a copy of your Excel Worksheet using "Save as" with a type of "CSV".
To use the Historic Import Wizard, select "Historic data -> Import" from your Data Source menu.
Keep the file type as "Delimited Text", browse for the CSV file that contains your records, and then choose the appropriate write mode (this will determine if your existing records will be replaced). Click Next, and you will be able to configure the parser to determine how the records in your CSV file are interpreted. Once the parser is configured, click Next and assign the newly defined series to new or existing Parameters. Finally, click Next and then click Finish to upload and process your file.
For the full documentation of this feature, please read http://docs.eagle.io/en/latest/topics/historic_data/import/index.html