Some of these are actually some remanants from development. They are mesh only tools. So to use you must first convert your object to a mesh. Select Convert to mesh and then click the left mouse button on the object to convert it to a mesh.
Join Joins two meshes together to form one object with one set of material coordinates. Select this option and click and hold the left mouse button on the object to join - while holding th eleft mouse button - drag the mouse pointer to the object you wish to join it to. (This options is the same as CSG->ADD)
merge points - no real use anymore - will become useful again when we have mesh editing tools
mesh morph - handy for freeform deforming meshes - convert the object to a mesh convert the view to wireframe so you can see Vertexes Click and drag right mouse button on polygon corners..
Regenerate Normals - HAndy for some imported objects when they are imported if they look inside out. Select this option and then click on the object
subdivide - Select this optiona nd click left mouse button ona object to add more polygons to the object (relevant when more mesh tools are available)
Subtract - Opposite of join. Select this option and click and hold the left mouse button on the object to subtract from - while holding the left mouse button - drag the mouse pointer to the object you wish to have subtracted from it. (this deletes the object you are subtracting - slightly different from the CSG ->Subtract which leaves the subtracting object int he scene)