The SIMATIC S7 Connector application allows you to import multiple data points or tags simultaneously from a TIA Portal project. You can select a file with the datapoints from the TIA Portal and export it from the TIA Portal and import it to the SIMATIC S7 Connector application. The file must correspond to the '.xml' file type.
In addition, S7-Protocol (S7-300/400/1200/1500) data source supports import of '.xls' file. The '.xls' format support is not from TIA Portal but from Tag Converter Tool.
For more information, refer How to Export Tags from TIA Portal?