The thing is that your table structure itself is wrong. You should normalize the table.
Let's consider that tax items on your goods get increased, in that case, you may have to add another column like tax2id and tax3name.
Rather I'd suggest you to normalize the table structure.
Use table structure like
InvoiceNo | TaxId | TaxName
------------------------------
1 2 VAT
1 3 SERVICE
2 1 Sales
2 2 VAT
And while retrieving the data, you can have something called 'Group By' clause.