Sorry I got distracted halfway through. I wanted to add if you don't want to manually create a local version of this table that has this column taken out you could do it dynmaically which would be more robust to future changes in the structure of t_header. Adding the following code into your routine should do the trick
data: lr_table TYPE REF TO cl_abap_tabledescr,
lr_old_str TYPE REF TO cl_abap_structdescr,
lr_new_str TYPE REF TO cl_abap_structdescr,
lt_comp TYPE cl_abap_structdescr=>component_table,
lr_new_tab TYPE REF TO cl_abap_tabledescr,
lr_local TYPE REF TO data.
FIELD-SYMBOLS: <lt_local> TYPE STANDARD TABLE,
<ls_local> TYPE ANY.
lr_table ?= cl_abap_tabledescr=>DESCRIBE_BY_DATA( t_header ).
lr_old_str ?= lr_table->GET_TABLE_LINE_TYPE( ).
lt_comp = lr_old_str->GET_COMPONENTS( ).
*replace COL with name of column that has type talbe
delete lt_comp where name = 'COL'.
lr_new_str = cl_abap_structdescr=>create( lt_comp ).
lr_new_tab = cl_abap_tabledescr=>create(
p_line_type = lr_new_str
p_table_kind = cl_abap_tabledescr=>tablekind_std
p_unique = abap_false ).
CREATE DATA lr_local TYPE HANDLE lr_new_tab.
ASSIGN lr_local->* TO <lt_local>. "INTERNAL TABLE.
data: ls_header like LINE OF t_header.
loop at t_header into ls_header.
APPEND INITIAL LINE TO <lt_local> ASSIGNING <ls_local>.
MOVE-CORRESPONDING ls_header to <ls_local>.
ENDLOOP.
cl_salv_table=>factory(
EXPORTING
r_container = ref_docking_hdr
IMPORTING
r_salv_table = ref_hdr
CHANGING
t_table = <lt_local> ).
ref_hdr->display( ).