Q:Whenever I try to use $ondelim and $offdelim to include a csv file containing a multi-dimensional (dimension >2) table I get into trouble (error 445).

Find below an example which illustrates how to do this. The trick is to delay the use of $ondelim, so GAMS can figure out what the structures is of the table (dimensions of the rows and columns).

Sets
   n 'scenario set'     /s0*s1100/
   i 'project set'      /i1*i3/
   para 'parameter set' /resv, ip, wresv, decay/
   ph 'phase set'       /ph1, ph2, ph3/
;
TABLE scen(n, i, para, ph) 'all data are logged and in csv format'
  i1.resv.ph1 i1.ip.ph1 i2.resv.ph1 i2.ip.ph1 i3.resv.ph1 i3.ip.ph1
$ondelim
$include scenpv.csv
$offdelim

option scen:6:3:1; display scen;

scenpv.csv

s1,    4.484497,    5.590780,    9.565448,   -2.776771,    2.017210,    0.403969
s2,    4.039559,    7.829553,    1.965880,    4.383472,    0.832007,    5.789936
s3,    2.557665,    2.588679,   18.390045,    1.562361,   -1.775599,   -1.249638
s4,    7.979709,    8.760805,   -0.482130,    7.159645,   13.708082,    1.417433
s5,    0.696502,    4.404599,    0.503611,    0.834050,   11.337872,   10.814183
s6,   18.435462,    2.077279,    5.328744,    0.618193,    6.188519,    3.306824
s7,    3.306904,    0.556912,   19.002177,    7.614140,   13.621738,    1.301998
s8,   10.388623,    8.810147,   11.926869,   -1.214278,   20.940576,    7.139113
s9,    7.147472,   10.465706,   14.562816,   11.444166,   -1.436094,   -2.144297
s10,    1.728924,    1.424648,    3.307312,    9.400273,    4.361133,    1.460645

----     23 PARAMETER scen  all data are logged and in csv format

                    ph1

s1 .i1.resv    4.484497
s1 .i1.ip      5.590780
s1 .i2.resv    9.565448
s1 .i2.ip     -2.776771
s1 .i3.resv    2.017210
s1 .i3.ip      0.403969
s2 .i1.resv    4.039559
s2 .i1.ip      7.829553
s2 .i2.resv    1.965880
s2 .i2.ip      4.383472
s2 .i3.resv    0.832007
s2 .i3.ip      5.789936
s3 .i1.resv    2.557665
s3 .i1.ip      2.588679
s3 .i2.resv   18.390045
s3 .i2.ip      1.562361
s3 .i3.resv   -1.775599
s3 .i3.ip     -1.249638
s4 .i1.resv    7.979709
s4 .i1.ip      8.760805
s4 .i2.resv   -0.482130
s4 .i2.ip      7.159645
s4 .i3.resv   13.708082
s4 .i3.ip      1.417433
s5 .i1.resv    0.696502
s5 .i1.ip      4.404599
s5 .i2.resv    0.503611
s5 .i2.ip      0.834050
s5 .i3.resv   11.337872
s5 .i3.ip     10.814183
s6 .i1.resv   18.435462
s6 .i1.ip      2.077279
s6 .i2.resv    5.328744
s6 .i2.ip      0.618193
s6 .i3.resv    6.188519
s6 .i3.ip      3.306824
s7 .i1.resv    3.306904
s7 .i1.ip      0.556912
s7 .i2.resv   19.002177
s7 .i2.ip      7.614140
s7 .i3.resv   13.621738
s7 .i3.ip      1.301998
s8 .i1.resv   10.388623
s8 .i1.ip      8.810147
s8 .i2.resv   11.926869
s8 .i2.ip     -1.214278
s8 .i3.resv   20.940576
s8 .i3.ip      7.139113
s9 .i1.resv    7.147472
s9 .i1.ip     10.465706
s9 .i2.resv   14.562816
s9 .i2.ip     11.444166
s9 .i3.resv   -1.436094
s9 .i3.ip     -2.144297
s10.i1.resv    1.728924
s10.i1.ip      1.424648
s10.i2.resv    3.307312
s10.i2.ip      9.400273
s10.i3.resv    4.361133
s10.i3.ip      1.460645

Below is an example of importing a 3 dimensional table.

Set s /s1/
    r /r1*r7/
    a /a1*a35/
;

$onecho > data.csv
,,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,a16,a17,a18,a19,a20,a21,a22,a23,a24,a25,a26,a27,a28,a29,a30,a31,a32,a33,a34,a35
s1,r1,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0
s1,r2,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0
s1,r3,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0
s1,r4,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0
s1,r5,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0
s1,r6,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0
s1,r7,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100,0,0,0,0,0,0,100
$offecho

Table csvtable(s,r,a)     3 dimensional table
$ONDELIM
$INCLUDE data.csv
$OFFDELIM
display  csvtable;