When editing a table with SLIME mode, pressing space causes the table to be malformed. The space is inserted in a plain-text way, as if the table was not recognized.
To reproduce: Turn on Lisp major mode and SLIME minor mode. Insert a new table. In one of the cells, start typing until
the column width begins to increase. Press space. The table is malformed.
I don't know if the incompatibility should/could be fixed in slime and/or in table.el.