Ok I've been able to reproduce your problem and also import data successfully.
I created a table like this, which I hope is similar to your table:
create table Book1
(
id int identity(1,1),
CompanyName varchar(20),
Segment varchar(20),
CustomerSegment varchar(20)
)
In my spreadsheet I had
CompanyName Segment CustomerSegment
Co1 seg1 cs1
Co2 seg2 cs2
which I hope is similar to your spreadsheet structure.
I then followed the Import wizard steps but ensured that the "Enable Identity Insert" checkbox was
not ticked.
The rows from my spreadsheet were all inserted into the table successfully