The ornamental design for a rollerboardassembly, as shown and described.
FIG. 1 is perspective view of a roller board assembly;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is an exploded view of the roller board assembly of FIGS. 1-7.
All broken lines are directed to environment and are for illustrative purposes only and form no part of the claimed design. The dash-dot broken lines depict boundaries of the claimed design and form no part thereof.