You can import from one excel table, twice--once into each table. But you need to be able to link the data in the two tables or it won't appear in the portal. If you have a common value that uniquely identifies each parent record (The layout's table), you can use it to link each record in the parent table to the newly imported records in the child (portal's) table. If this common value is not what you use in your relationship, you can define a second relationship based on this other value and then a script or replace field contents can use this relationship to copy over the ID number to the child table.
If not, then you'll need to import into a temporary table and use a script that moves the data into each record of each table one row at a time and it can use the ID number from the newly generated parent record to link it to any new child records.
Thank you for taking your time to answer. I will proceed to follow your instructions. To import data from foreigner files into related tables is not as easy as one-two-three. Thanks again
Thank you for taking the time to answer my question. Importing data from foreigner files into related tables is not as easy as one-two-three. I forsee a lot of manual handling,especially when having hundreds of records to import. Thanks again.