Before loading very large data files, see the workspace option Preload All Data. This option can be used to enable lazy loading, which can drastically speed up load time.
From the Data branch context menu in the workspace tree, select Load Dataset from File.
This will invoke the Open Data File dialog. Select a supported data source file and click the OK button.
After a dataset is loaded into your workspace, the file name and the file path are automatically added to the data reference table. The corresponding check box is unchecked to indicate its de-linked status.