A set of values for a range having a lower and upper limit can be uploaded into a report variant all you need to do is seperate the values with the value '&&'.
Setup the value ranges in a spreadsheet and then cut paste the concatenated values column into a text file.
For example in Excel with formula " =CONCATENATE(A1,"&&",B1)"
Col1 Col2 Concatenate with '&&'
101 105 101&&105
110 115 110&&115
120 125 120&&125
130 135 130&&135
140 145 140&&145
150 155 150&&155
160 165 160&&165
170 175 170&&175
180 185 180&&185
190 195 190&&195
200 205 200&&205
Text file then will look like this
101&&105
110&&115
120&&125
130&&135
140&&145
150&&155
160&&165
170&&175
180&&185
190&&195
200&&205
Then when you are in the 'Select Ranges' tab for entering the Multiple Selection use 'Shift-F11' to read the text file values into SAP.