Multiple Filters using linq

I am trying to implement multiple filter using Linq.
I want to extract the rows from excel where:
Col A has blank row and Col B is Numeric.

Issue: Col B has Data as: 1234 5678; 12345678 etc. i.e., I need to ignore the blanks in this case and extract the data table.
I was using datatable.select method, which is working fine, but want to reduce the number of steps and complexity.

Can anyone assist me here?