Tabs too large

Once you select the cut line or shape in Easel (see image below), a window will popup with the cut specifications. From this window you can select cut depth, the type of cut (pocket, on shape path, etc.). At the bottom you can select whether or not you want to use tabs, how many tabs, the length of the tabs and the height of the tabs.

The, “length”, will resize the tabs for you.

You may also, “grab”, a tab and move it to any position you wish.

That works for a 2D not 3D that I could see.

Correct, tabs in 3d can be moved, but the size (height or length) cannot be edited at this time.

Side note, your project isn’t shared properly, the only one that can open it is you, while logged into your account…
the 2nd half of this video shows the process to share an easel project so that the link you provided will work for others…