It's hard to understand your English. A screenshot might help, as would more detail.
What do you mean by "mark"? Surely not just select?
And if you do mean, select, what do you want to do after you have selected them? Did you try Cmd/Control A?
As long as the tables are contiguous you can select as many or as few as you like (ID cannot select dis-contiguous text) by placing the cursor in front of the first table and either dragging down to where you want to stop, or hold the shift key and click after the last table you want.