The formats of entries in the table of contents (TOC) are
controlled by a number of internal commands (discussed in section 2.3
of The LaTeX Companion - see
TeX books). The commands
\@pnumwidth, \@tocrmarg and \@dotsep control the space
for page numbers, the indentation of the right-hand margin, and the
seperation of the dots in the dotted leaders, respectively. The
series of commands named \l@xxx, where xxx
is the name of a sectional heading (such as chapter or
section, ...) control the layout of the corresponding
heading, including the space for section numbers. All these internal
commands may be individually redefined to give the effect that you
want.
Alternatively, the package tocloft provides a set of user-level commands that may be used to change the TOC formatting. Since exactly the same mechanisms are used for the List of Figures and List of Tables, the layout of these sections may be controlled in the same way.
The KOMA-Script classes provides an optional variant structure for the table of contents, and calculates the space needed for the numbers automatically. The memoir includes the functionality of tocloft.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=tocloft