Writer's table properties currently offers the following alignment options: ( ) Automatic ( ) Left ( ) From Left ( ) Right ( ) Center ( ) Manual this is problematic in many ways, see bug 145980. What that bug does not cover, however, is the need to be able to align the table with the Start or End, as opposed to aligning Left or Right. I believe Start and End in this context will correspond to the table's direction (currently appearing in the UI as its "text direction").
Just to be clear, of course - I don't think it's a good idea to have 8 (!) different alignments on offer. But that's a matter for discussion in bug 145980.